I'm not an expert on marketing by any means so take it with a grain of salt but my impression is that testimonials are more effective when you tell about your personal experience instead of just saying "x is y". So if you could say what Mastodon enabled you to do or what it means to you that would be a lot better than if you just said that Mastodon has something.
@Gargron Mastodon gave me a new home after Twitter turned toxic.