Facebook CEO Mark Zuckerberg says he's not running for president, but a recent nationwide tour has been stoking speculation.

In the past few months, Zuckerberg has visited military bases, dined with "folks" in Ohio, and even been photographed working on the assembly line of a Ford factory — stuff people usually do when they're starting a political campaign.

So, he's running, right? Not so fast, says Nathan Hubbard, the former CEO of Ticketmaster. In a widely shared tweetstorm over the weekend, he laid out another possible reason to explain why Zuckerberg was crisscrossing the US and looking like a political candidate.

Basically, Hubbard says, Zuckerberg is acting like the product-focused CEO he is. Hubbard believes Zuckerberg initially didn't understand Facebook's role in last year's election and the political discourse, and now he's trying to understand — as a product guy — how Facebook may have contributed to President Donald Trump's election.