Not everyone agrees with Dorsey, of course, which is why Geist asked how he responds to critics who say Twitter is simply giving Trump a platform to bully fellow politicians or to bash the media.
Some have argued that Trump’s tweets violate Twitter’s harassment policies. He believes that, without Twitter, the kinds of “conversations” that Trump’s tweets inspire would simply disappear from the public eye.
Critics argue that he is using his huge following to bully his opponents and promote untruths, and that as a result he should be shut down like any other account would.
Mr Dorsey said that in fact having Mr Trump's tweets out in the open help keep people informed and that without them the public would know a lot less about their leaders.
That disappointed investors who were expecting a "Trump bump" caused by the US president's constant tweeting.
Donald Trump's tweets about pop stars: "He's known how to use it for quite some time.
It's no secret that the presidential election and the following Cabinet appointments and events following president-elect Trump's win in November have created quite the frenzy on social media.
It seems that you can't scroll through your Facebook newsfeed or read more than two tweets without at least one (usually emotion-fueled) reference to Trump, Clinton or politics in general.
There's at least one person who loves Twitter a whole lot: co-founder Jack Dorsey.
The CEO on Valentine's Day tweeted out his affection for his popular, yet struggling social network, complete with the hashtag #Love Twitter.