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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Chevron enters the lithium market with major Texas land acquisition

to market

Chevron U.S.A., a subsidiary of Houston-based energy company Chevron, has taken its first big step toward establishing a commercial-scale lithium business.

Chevron acquired leaseholds totaling about 125,000 acres in Northeast Texas and southwest Arkansas from TerraVolta Resources and East Texas Natural Resources. The acreage contains a high amount of lithium, which Chevron plans to extract from brines produced from the subsurface.

Lithium-ion batteries are used in an array of technologies, such as smartwatches, e-bikes, pacemakers, and batteries for electric vehicles, according to Chevron. The International Energy Agency estimates lithium demand could grow more than 400 percent by 2040.

“This acquisition represents a strategic investment to support energy manufacturing and expand U.S.-based critical mineral supplies,” Jeff Gustavson, president of Chevron New Energies, said in a news release. “Establishing domestic and resilient lithium supply chains is essential not only to maintaining U.S. energy leadership but also to meeting the growing demand from customers.”

Rania Yacoub, corporate business development manager at Chevron New Energies, said that amid heightening demand, lithium is “one of the world’s most sought-after natural resources.”

“Chevron is looking to help meet that demand and drive U.S. energy competitiveness by sourcing lithium domestically,” Yacoub said.

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This article originally appeared on EnergyCapital.

International Space Station welcomes astronauts from successful Axiom Mission 4

Out In Space

The first astronauts in more than 40 years from India, Poland and Hungary arrived at the International Space Station on Thursday, ferried there by SpaceX on a private flight.

The crew of four will spend two weeks at the orbiting lab, performing dozens of experiments. They launched Wednesday from NASA’s Kennedy Space Center.

America’s most experienced astronaut, Peggy Whitson, is the commander of the visiting crew. She works for Axiom Space, the Houston company that arranged the chartered flight.

Besides Whitson, the crew includes India’s Shubhanshu Shukla, a pilot in the Indian Air Force; Hungary’s Tibor Kapu, a mechanical engineer; and Poland’s Slawosz Uznanski-Wisniewski, a radiation expert and one of the European Space Agency’s project astronauts on temporary flight duty.

No one has ever visited the International Space Station from those countries before. The time anyone rocketed into orbit from those countries was in the late 1970s and 1980s, traveling with the Soviets.

“It’s an honor to have you join our outpost of international cooperation and exploration," NASA's Mission Control radioed from Houston minutes after the linkup high above the North Atlantic.

The new arrivals shared hugs and handshakes with the space station's seven full-time residents, celebrating with drink pouches sipped through straws. Six nations were represented: four from the U.S., three from Russia and one each from Japan, India, Poland and Hungary.

"It’s so great to be here finally. It was a long quarantine," Whitson said, referring to the crew's extra-long isolation before liftoff to stay healthy.

They went into quarantine on May 25, stuck in it as their launch kept getting delayed. The latest postponement was for space station leak monitoring, NASA wanted to make sure everything was safe following repairs to a longtime leak on the Russian side of the outpost.

It's the fourth Axiom-sponsored flight to the space station since 2022. The company is one of several that are developing their own space stations due to launch in the coming years. NASA plans to abandon the International Space Station in 2030 after more than three decades of operation, and is encouraging private ventures to replace it.

Screen-free hiking app developed in Houston earns 'Best of the Best' award

Peak Prize

An AI-powered, screen-free hiking system developed by Varshini Chouthri, a recent industrial design graduate from the University of Houston, has received Red Dot’s “Best of the Best” award, which recognizes the top innovative designs around the world.

Known as NOMAD, the system aims to help users stay in the moment while still utilizing technology. It will go on to compete for the Red Dot Luminary Award, the highest recognition given at the international event.

“NOMAD was truly a passion project, inspired by years of hiking growing up, where the outdoors became a place of peace, challenge, and reflection,” Chouthri said in a news release.

“I wanted to design something supporting those kinds of experiences by helping hikers feel more grounded and confident while staying present in nature. It was a way to give back to the moments that made me fall in love with the outdoors in the first place.”

The app “reimagines” outdoor exploration by removing the dependence on screens by using adaptive AI, contextual sensing, and an optional, wearable companion device. It employs a circular learning model that enables hikers to receive real-time guidance, safety alerts, personalized trip planning, hands-free navigation and more through a natural interface, according to UH.

NOMAD was developed at the Hines College of Architecture and Design’s PXD LAB. In 2023, Lunet, developed by David Edquilang at Hines College, received the “Best of the Best” recognition and went on to win the Red Dot Luminary Award.

The PXD LAB offers a platform to expand concepts into system-level designs that address real-world challenges, according to UH.

“Varshini’s work on NOMAD exemplifies the future-focused, systems-driven thinking we promote in the Advanced UX Design curriculum,” Min Kang, director of PXD LAB, added in the release. “NOMAD goes beyond being just a product; it reimagines how technology can enhance outdoor exploration without disrupting the experience.”

In addition to the Red Dot honors, NOMAD has already earned distinction from the FIT Sport Design Awards and was a finalist for the International Design Excellence Awards (IDEA) presented by the Industrial Designers Society of America.
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