Chat spaces help to build relationships with other community members. Forums are focused on topics over individuals which is generally a good thing, but there is a space for more informal conversations that help bond over shared interests.
Just to expand a bit on things that I think makes chat more comfortable for me to participate in some conversations:
I have lower expectations for making “good posts”. Shorter messages are fine
less likely to be “seen forever” so if I’m less worried that something I say silly will be found 3 months from now.
Yep, even in public channels in chat space, it’s common to see people form group identities within the channels they have chosen to join. I can make some stronger assumptions about who I’m having a particular conversation with, and that can contribute to building relationships and comfort as well.
I sometime prefer engaging in chat when I’m on a mobile device. (I’m also happy to read longer posts on mobile, but I’m a bit less likely to contribute until I have a real keyboard).
We launched a new product feature where a live chat event highlights questions to be answered and this is all converted into a normal forum topic at the end of the event to retain the conversation and allow others to contribute that weren’t at the event.
I feel this brings balance in that you can have a live informal chat to get to know other members, but the best content of that chat is preserved into the lifeblood of any forum: topics and posts.