Different earning system for different interests?

Tweet

I've read somewhere (somewhere being someone else's discussion thread) that no one knows exactly how mylot tallies your earnings, but I was wondering if anyone knows if posting in different interest reaps differing earnings. I was just curious because, compared to two days ago, I was definitely more active yesterday but I got a vastly lower earning rate. I don't really start discussions (as an aside: is there a difference between starting a discussion and continuing an already on-going one?), but I do make it a point to keep my posts longer than three sentences, and I would like to think that my posts aren't spam-ish (I state what I like/dislike and some more personal opinions) and as far as I know, no posts have been deleted yet. I am new though, so I am not yet fully used to the place. So I'm now wondering whether I missed something altogether. I got side-tracked but, yes: do posting on different interests have an effect on the earnings one get? Because I am just really wondering. Does anyone know?