Houston founder shares how he's using tech to make digital media more effective and equitable

houston innovators podcast episode 173

This month, Mark Walker is celebrating his company's one year anniversary of going public — only the ninth Black-founded business to accomplish this feat on a U.S. stock exchange. Photo courtesy

After working in both sides of the advertising world, Mark Walker thought he could reimagine a platform that would be more efficient and equitable.

Walker co-founded his company, Direct Digital Holdings, an adtech platform, after serving in several roles — from an early hire at Houston digital media startup Questia to business development director at NRG Energy and COO of EBONY Media. He shares on the Houston Innovators Platform how he took this experience in tech, advertising, and media to create his company's platform.

"NRG Energy gave me a top-down view of the value chain, and Ebony gave me a bottoms-up view of the value chain of how media is purchased," Walker says on the show. "At Direct Digital Holdings, we help companies buy and sell media — and we leverage technology to do it. It's really the culmination of both of those experiences."

With over 30,000 publishers on its platform, Direct Digital makes it easier for its core customers — middle market companies looking to buy into the digital media ecosystem — to tap into these opportunities without the tech know-how they might otherwise need. Walker explains that at EBONY, he saw how small to midsize publications — especially the multicultural ones — were being left out on the ad selling side of the equation. The Direct Digital platform bridges the gap on each end.

Founded in 2018 in partnership with Keith Smith, who went through similar professional experiences, Direct Digital went public exactly one year ago after growing the company through strategic M&A activity. Walker says the decision to IPO made the most sense for his company — though it wasn't an easy process. Direct Digital is only the ninth company founded by a Black entrepreneur to go public on a US stock exchange.

"If you think the process is hard — it actually is," Walker says on the journey to IPO. "We were a privately held company, and we knew we had a good growth trajectory and we looked a couple different options. We decided to go public in a very traditional way."

Walker explains there were some risks involved, but the co-founders ultimately decided to shy away from adding in investors who might not have the same ideas for the company's future.

Direct Digital has been a Houston company from the star — despite the city not being home to a booming adtech ecosystem. Instead, Houston — with its collection of Fortune 500 companies and rich diversity — has allowed the business to stand out.

"If you look at and reflect on how our company has been built — from our board of directors to our leadership and management team — we're a majority minority organization all the way across the board," Walker says. "Diversity is very important to us. It's the lifeblood of our business — especially because we're serving publishers in those communities in big way. And moreso, we think you get the best product, thoughts, and ideas from a diverse workforce, and Houston fits right into that mold for us."

Walker shares more about his company's future, advice on IPO, and what all he's watching in adtech — from AI to streaming — on the podcast. Listen to the interview below — or wherever you stream your podcasts — and subscribe for weekly episodes.


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Houston-based HPE wins $931M contract to upgrade military data centers

defense data centers

Hewlett Packard Enterprise (HPE), based in Spring, Texas, which provides AI, cloud, and networking products and services, has received a $931 million contract to modernize data centers run by the federal Defense Information Systems Agency.

HPE says it will supply distributed hybrid multicloud technology to the federal agency, which provides combat support for U.S. troops. The project will feature HPE’s Private Cloud Enterprise and GreenLake offerings. It will allow DISA to scale and accelerate communications, improve AI and data analytics, boost IT efficiencies, reduce costs and more, according to a news release from HPE.

The contract comes after the completion of HPE’s test of distributed hybrid multicloud technology at Defense Information Systems Agency (DISA) data centers in Mechanicsburg, Pennsylvania, and Ogden, Utah. This technology is aimed at managing DISA’s IT infrastructure and resources across public and private clouds through one hybrid multicloud platform, according to Data Center Dynamics.

Fidelma Russo, executive vice president and general manager of hybrid cloud at HPE, said in a news release that the project will enable DISA to “deliver innovative, future-ready managed services to the agencies it supports that are operating across the globe.”

The platform being developed for DISA “is designed to mirror the look and feel of a public cloud, replicating many of the key features” offered by cloud computing businesses such as Amazon Web Services (AWS), Microsoft Azure and Google Cloud Platform, according to The Register.

In the 1990s, DISA consolidated 194 data centers into 16. According to The Register, these are the U.S. military’s most sensitive data centers.

More recently, in 2024, the Fort Meade, Maryland-based agency laid out a five-year strategy to “simplify the network globally with large-scale adoption of command IT environments,” according to Data Center Dynamics.

Astros and Rockets launch new streaming service for Houston sports fans

Sports Talk

Houston sports fans now have a way to watch their favorite teams without a cable or satellite subscription. Launched December 3, the Space City Home Network’s SCHN+ service allows consumers to watch the Houston Astros and Houston Rockets via iOS, Apple TV, Android, Amazon Fire TV, or web browser.

A subscription to SCHN+ allows sports fans to watch all Astros and Rockets games, as well as behind-the-scenes features and other on-demand content. It’s priced at $19.99 per month or $199.99 annually (plus tax). People who watch Space City Network Network via their existing cable or satellite service will be able to access SCHN+ at no additional charge.

As the Houston Chronicle notes, the Astros and Rockets were the only MLB and NBA teams not to offer a direct-to-consumer streaming option.

“We’re thrilled to offer another great option to ensure fans have access to watch games, and the SCHN+ streaming app makes it easier than ever to cheer on the Rockets,” Rockets alternate governor Patrick Fertitta said in a statement.

“Providing fans with a convenient way to watch their favorite teams, along with our network’s award-winning programming, was an essential addition. This season feels special, and we’re committed to exploring new ways to elevate our broadcasts for Rockets fans to enjoy.”

Astros owner Jim Crane echoed Feritta’s comments, adding, “Providing fans options on how they view our games is important as we continue to grow the game – we want to make it accessible to as large an audience as possible. We are looking forward to the 2026 season and more Astros fans watching our players compete for another championship.”

SCHN+ is available to customers in Texas; Louisiana; Arkansas; Oklahoma; and the following counties in New Mexico: Dona Ana, Eddy, Lea, Chaves, Roosevelt, Curry, Quay, Union, and Debaca. Fans outside these areas will need to subscribe to the NBA and MLB out-of-market services.

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This article originally appeared on CultureMap.com.

Rice University researchers unveil new model that could sharpen MRI scans

MRI innovation

Researchers at Rice University, in collaboration with Oak Ridge National Laboratory, have developed a new model that could lead to sharper imaging and safer diagnostics using magnetic resonance imaging, or MRI.

In a study recently published in The Journal of Chemical Physics, the team of researchers showed how they used the Fokker-Planck equation to better understand how water molecules respond to contrast agents in a process known as “relaxation.” Previous models only approximated how water molecules relaxed around contrasting agents. However, through this new model, known as the NMR eigenmodes framework, the research team has uncovered the “full physical equations” to explain the process.

“The concept is similar to how a musical chord consists of many notes,” Thiago Pinheiro, the study’s first author, a Rice doctoral graduate in chemical and biomolecular engineering and postdoctoral researcher in the chemical sciences division at Oak Ridge National Laboratory, said in a news release. “Previous models only captured one or two notes, while ours picks up the full harmony.”

According to Rice, the findings could lead to the development and application of new contrast agents for clearer MRIs in medicine and materials science. Beyond MRIs, the NMR relaxation method could also be applied to other areas like battery design and subsurface fluid flow.

“In the present paper, we developed a comprehensive theory to interpret those previous molecular dynamics simulations and experimental findings,” Dilipkumar Asthagiri, a senior computational biomedical scientist in the National Center for Computational Sciences at Oak Ridge National Laboratory, said in the release. ”The theory, however, is general and can be used to understand NMR relaxation in liquids broadly.”

The team has also made its code available as open source to encourage its adoption and further development by the broader scientific community.

“By better modeling the physics of nuclear magnetic resonance relaxation in liquids, we gain a tool that doesn’t just predict but also explains the phenomenon,” Walter Chapman, a professor of chemical and biomolecular engineering at Rice, added in the release. “That is crucial when lives and technologies depend on accurate scientific understanding.”

The study was backed by The Ken Kennedy Institute, Rice Creative Ventures Fund, Robert A. Welch Foundation and Oak Ridge Leadership Computing Facility at Oak Ridge National Laboratory.

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