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- REX End of Year Update: TY, Techstars!
REX End of Year Update: TY, Techstars!
Happy Holidays everyone!

Thank you, Techstars!
Wanted to say a HUGE thank you to Tricia and team over at Techstars AI Chicago for believing in us since Day 1.
She saw the future and believed in us as THE team to usher it in.
Humbled. Humbled. Humbled.
2024 Top 5
Here are the top 5 things we accomplished in our 1st year of existence that I’m most proud of:
Techstars AI. Undoubtably, getting through Techstars AI was our biggest accomplishment of 2024. Only 1% of folks get selected, we learned a shitload about our customer, product, and ourselves individually and collectively as a company. It definitely did “accelerate” us across all dimensions and functions and introduced us to an awesome group of fellow founders and network!
Focus. Focus. Focus. When we started, we were all over the place. We wanted to do content, social, automate influencer, etc. However, after we talked to Alyson and about 100 potential customers, we decided to focus on what: A) moves the needle for businesses and B) is the biggest pain in the ass for an SMB - omnichannel digital advertising.
AdTech Pilot. We chose 170 ecomm brands to do ad campaigns with over 4 months with $10M in ad spend across Google, Meta, Amazon and returned 9X ROAS, which is 3X the average. It worked! 🙂 This was a HUGE moment for the team as it validated the backend 10+ martechstack across 30+ ad channels.
Rebrand. We started out with MarketBloc when we were going to be all things to everyone. Once we focused, we realized that the name of the AI Chief Marketing Agent, REX, would be a much better product and company name. Thanks to Alyson and Matty W for his incredible brand work! 🙂
Teamwork. As is the case with all startups (and this is my 4th!) the team, including co-founders, founding partners, employees, contractors, investors and partners, is always changing. Some folks come and go, others find other opportunities, some aren’t the right fit for the stage, some you have to let go… However, through it all, we have had a core group of teammates that are down for the cause, no matter what. These are the folks you come to work for every single day. These are the ride or die folks that help you build a company. These are the folks that are there with you through thick and thin. Everyone played a part getting us to where we are today and for that I’m eternally grateful.
Honorable Mentions
Raising a F&F Round. The environment was tough this year to raise pre-revenue and pre-product, even for AI! I also think adtech/martech is a really tough space to truly understand distinctiveness and expertise if you haven’t been in it for the past 15 years like us! 🙂 However, we did it! Congrats to our investors and friends and family who believe in the mission and the team. Humbled. Thank you.
Starting to Build the SLM. “REX’s brain” is what we call it, and it is our moat. You have the collective knowledge of 4 x senior c-suite marketing, martech, advertising professionals with a combined 100 years of experience growing companies across categories to millions and billions in revenue via digital ads.

Sean & Nikhil at Techstars AI inside Google - Chicago
“Alone it is just a journey. Now adventures, they must be shared!” - The Hobbit
2025 is the year we start our adventure that will lead to REX becoming one of the Big 5 Ad Agencies and helping millions of customers along the way.
However, REX will not just serve the 100+ biggest clients we can find.
We want to give access to REX’s brain to millions of SMBs in a way that is affordable, on-demand and easy. No more Big 5 ivory towers!
VISION: A future where every startup has equal access to a Big 5 ad agency
REX will serve tens of millions of small and mid-sized businesses.
We will be the Agent(cy) of the People.
Accessible: Available 24/7/365 vs. once a week
Affordable: Starts at $100/mo vs. $10k/mo minimum
AI Agent centric: Not human-centric
Actual science and evidence-based marketing: Not pseudoscience or anecdotal evidence

MISSION: The REX Team provides on-demand, affordable and easy access to Big 5 ad agency knowledge, skills and capabilities 24/7/365 online and mobile in order to (IOT) even the playing field for SMBs.
Note: Can you tell I was a senior Army officer and worked at the Pentagon with that mission statement? 🙂
Our mission is to democratize digital marketing for everyone, starting with advertising.
We all know that digital advertising is the lifeblood of business in today’s world.
Without it, you cannot reach new customers and every business needs new customers to maintain growth.
However, for way too long, omnichannel advertising across Google, Meta, Amazon and 25+ other ad channels have been inaccessible to the masses.
You only had 2 options:
1. Build an expensive in-house marketing team or
2. Hire an agency
This makes growth almost impossible for small and medium sized businesses as both options require your FIRST $10k-a-month to go to a human and NOT digital advertising on Google, Meta or Amazon.
The Solution: REX, your Chief Marketing Agent
REX is the world’s first AI Chief Marketing Agent, buying ads across 30+ ad channels.
He will deal with the craziness that is digital advertising in a super simple and easy way for founders.
Based on our Marketing SLM, he already knows WHAT to do, HOW to do and will do it FOR them.
In fact, they don’t even need to create any ad accounts!
He will just show them the results.
VALUES: How we will get there
It won’t surprise anyone that I use the military’s value system and leadership and management philosophies, techniques and exercises to drive productivity, mission-first mentalities and team-building.
The Army was the single best leadership and management training I received and I’m truly grateful for the trust and opportunities they gave me to learn and fail over and over again until I got leadership and management right.
In that regard, the Tech Industry and the Army aren’t so different. 🙂
R.E.S.I.L.I.E.N.T
R - Radical Responsibility
What It Means: We own our actions, outcomes, and their impact on others. Like the Stoics, we focus on what we can control. Radical responsibility means acknowledging both our strengths and shortcomings without excuses or blame-shifting.
In Practice (3 Up, 3 Down):
3 Up (What Went Well):
Identify three specific successes or strengths from the task or project.
Celebrate actions or decisions that aligned with core values.
Acknowledge positive impacts or outcomes delivered by the team or individual.
3 Down (What Needs Improvement):
Pinpoint three areas where actions or decisions could be improved.
Focus on behaviors or processes—not individuals—for constructive feedback.
Provide actionable solutions or next steps to address these shortcomings.
E - Excellence Always
What It Means: Excellence isn’t a goal—it’s the starting point. We demand high standards of ourselves and others, holding one another accountable with honesty and respect.
In Practice:
Use Post-Mortem Reviews to evaluate how standards were met or missed.
Reinforce radical candor to continuously raise the bar and drive improvement.
S - Self-Awareness First
What It Means: Growth starts with understanding ourselves. Self-awareness fuels personal and professional development, and feedback is a tool, not a criticism.
In Practice:
Regularly conduct "3 Up, 3 Down" self-assessments to reflect on strengths and growth areas.
Share reflections openly with the team to foster vulnerability and mutual learning.
I - Impact Over Intentions
What It Means: Results drive change and growth. While intentions are important, they don’t outweigh the need for delivering measurable impact.
In Practice:
Use radical candor to evaluate actions based on outcomes, not effort alone.
Highlight clear metrics and results to measure success and improve processes.
L - Leadership Through Service
What It Means: We lead by enabling others to succeed. Leadership isn’t about authority—it’s about empowering the team and fostering trust.
In Practice:
Leaders model radical accountability by owning mistakes and prioritizing team needs over personal wins.
Use feedback loops to ensure leadership is meeting the team’s expectations and evolving as needed.
I - Integrity in Transparency
What It Means: We communicate openly, honestly, and without pretense. Transparency builds trust and strengthens team cohesion.
In Practice:
Hold open debriefs to discuss successes and failures constructively.
Share data, decisions, and lessons learned freely to align the team and encourage trust.
E - Empathy Without Ego
What It Means: We listen to understand, not to respond. Empathy fosters collaboration and constructive feedback while avoiding ego-driven interactions.
In Practice:
Combine radical candor with empathy to address behaviors, not personalities.
Actively listen to teammates, ensuring everyone’s input is valued and respected.
N - Never Stop Learning
What It Means: Growth is a continuous journey. We approach challenges with curiosity and acknowledge that no one knows everything.
In Practice:
Encourage self-assessments using the "3 Up, 3 Down" method to identify areas for improvement.
Treat mistakes as opportunities for learning and celebrate efforts to grow.
T - Team Over Self
What It Means: Collaboration and collective success come first. Shared goals take priority over individual achievements.
In Practice:
Evaluate team-wide performance using shared success metrics.
Next Steps
Since we started, we’ve done over 170 campaigns with over $10M in ad spend achieving a 9X ROAS for our ecomm partners (3x the industry average).
Now we are FINALLY ready to onboard NEW customers starting in 2025.
We have a waitlist of 10,000 businesses that are ready to go and we believe we will hit $4M ARR by the end of the year.
Buckle up all of you current and potential future investors!
The future is here.
Thank you ALL for supporting us since Day 1, either with your kind words, candid feedback or cheers/sparse clapping from the sidelines.
See you on the flip side in 2025!
Help Needed
As we get ready for our Q1 launch we need two (2) things:
Focus Area #1: Building our Seed investor list. Right now we have the Techstars Investor Reveal in the 2nd week of January where they blast this out to their entire network. We have built a carefully curated list of seed angels ($100k+) and funds/family offices ($250k - $1M checks) as well.
Call To Action (CTA) #1: Please send us any angels or funds to include on the outreach list. Unfortunately, we can only have 2-3 institutional partners in this round, so please only send us folks who are ride or die, founder-friendly, and add a ton of value besides investment dollars.
Focus Area #2: Building our Alpha list of customers. Right now we have a 10k company waitlist. We will start onboarding en masse in Q1.
CTA #2: If you have any portcos, especially CPG/ecomm, that you want us to prioritize that need help with marketing, let me know personally and I’ll move them to the front.
Happy Holidays & Happy New Year!!!
PS. Look how cute our dog Lambchop is in front of the Merch Mart Xmas tree! 🙂 Big congrats to Lambie for finishing her Service Dog training!!!

In case you didn’t know, my name is Sean Gilfillan and I am personally going to revolutionize the entire $2.5T digital marketing and advertising industry.
Why?
Because I didn’t die in Iraq.
I made it back.
So unless someone is shooting at me, I ain’t going to ever give up.
Clawed my way up to work at the Pentagon.
Then became a US Diplomat.
Spokesperson for US Embassy Warsaw.
Then built BaseFEST because troops weren’t getting to see A-list talent.
Brought on 50+ Fortune 500 brands and launched an entire $3B defense industry around 3rd party events on base when others said it was impossible.
Became the “go-to” agency of record for Fortune 500 clients who wanted to spend $10s of millions in digital advertising on Google, Facebook to boost their military bonafides.
Sold that company in 2019.
And now I’m pissed off AGAIN.
Why?
Pissed that SMBs and portcos have no better options than hiring some expensive ass agency that gives them an entry-level employee account exec and one hour a week.
Until you pay them MORE money.
No, no, no, no.
That’s just wrong.
SMBs don’t have the time or money to do that!
They need to spend that precious money on growing via digital advertising!
The model has to change.
And it has to be led by marketers with backgrounds in marketing science, i.e. How Brands Grow and evidence-based marketing, not anecdotal or pseudoscience bullshit.
Come along for the adventure. 🙂
You won’t regret it.
Thanks for reading this newsletter and passing it along to others who want to follow along.