I am not going to answer your question since I don't have any side projects. But, I think the similar question was asked by a HN user a month ago. Ah, here is the thread.

Ask HN: Those making $0/month or less on side projects – Show and tell - https://news.ycombinator.com/item?id=34547265 (1048 comments)

Hopefully, above thread also gives you some insight.