I’ve had requests from agents, but they all resulted in pretty quick form rejections. I’ve tried it with two different books, and I definitely had the most requests the first time I did each of them, even though people say to try them again at later events because different agents check in (and not all agents see all the tweets in one event anyway). I don’t know if that’s just because these events get more and more popular (to writers, not necessarily to agents or editors), which makes it less likely your tweet will be seen.
But there are definitely stories of people who have found agents through pitch parties. So it happens. But there are just so many pitches versus so little agents, so many people will get few or no requests, let alone successfully find an agents.
Honestly, I just kind of enjoy them because it’s fun coming up with pitches and it’s fun seeing and promoting other people’s pitches. I also like to use upcoming pitch parties as deadlines for myself, because otherwise I would probably never finish editing a book lol. (I LOATHE revising/editing). But I don’t honestly go into them with much expectation for success.