Tbh it's not something you're likely to make a lot of income from though, not unless you have a LOT of traffic. Ad revenues are poor anyway so premium listings get the most $'s, and that needs traffic before you can charge good prices. Try the free scripts first, you can always upgrade later but you don't want to be spending a lot because of the poor initial returns. It's a learning experience the same as proxies, do it, try new stuff, see what works for you. I only started my list because I wanted somewhere to list my own proxies in the first place but it kind of grew :D, so I started another and hope to do some more eventually. Everybody needs a hobby.