Understanding the people you tweet with is, of course, a great way to determine if offsite connections are going to be worth it. After all, offsite connections that are hundreds of miles away are not likely to be easy, cheap, or even possible.
On much of social media, when you are an independent author, you lead two lives. There is your personal life where you have friends and family, but there is also your professional or semi-professional life. Even if you never sell (or never want to) a syllable of your work, if you want to improve, you're at least in the realm of semi-professional.
Because sticking a bunch of people into a windowless room and telling them to be creative is going to be about as effective as sticking a gun to their heads and commanding that they write a guaranteed hit song.