[1] Steinberg is a serial entrepreneur, one of few who have built multiple companies that are worth $1 billion dollars, and do more than $100 million in annual sales.

[4][5] In 1993, David Steinberg founded Sterling Cellular, Inc. in the basement of his house in Bethesda, Maryland with the use of credit cards and a parental loan.

[11] In November 2007, after Steinberg resigned as CEO and chairman of the board,[12] InPhonic filed a Chapter 11 petition in the United States Bankruptcy Court for the District of Delaware.

Zeta Global, (formerly Zeta Interactive) was originally built through several small companies specializing in different facets of online marketing and CRM that were acquired and combined to create the firm which has now grown into a full-service big data, customer acquisition, and customer relationship management services.

[22] Again in 2015, Steinberg helmed Zeta Global as it acquired the customer relationship management division of eBay's Enterprise operation, in a deal that sources near the company said was worth US$80–90 million.

[1] Zeta Global has the industry's third largest data set (2.4B+ identities), next to Google and Facebook, powered by demographic, locational, behavioral, transactional, and predictive signals.

Zeta Global announced on March 1, 2021, that the company had raised $222.5 Million in their most recent debt financing funding round.