These are companies that buy wireless service from the three big US carriers and re-sell it. It’s an attractive arrangement for the big carriers since they may have extra network capacity that would otherwise go unused. In 2019 he bought an ownership stake in Mint Mobile, an MVNO using the T-Mobile network, and became the brand’s spokesperson. Greengart thinks that was a tipping point for the MVNO business, or at least, the celebrities-backing-MVNOs business. Either way, I don’t think this is the last time we’ll hear from a public figure ready to sell us wireless service.