How do subscriptions work?

[a profile name]

So I set revenue to be subs on my secondary business but for some reason they seem to be a lot less that $4 per month per registered user. Why is this? How much do they actually earn?

[tibobn]

subs seem to work with who want to actualy pay for the feature ... like real life not everyone is interested in paying sub for everything a site offer i guess .. if that make sense ...