50% of the people on my blog, click thru to an affiliate link. Of that 50% , more than 1/3 of them will at least download a song. It's gone up a lot in the last 4 weeks for some reason (Mystified) This blog: 124 Beats Per Minute, and the store has gotten a lot more traffic since I put up the video in the 300x250 ad spot. Little things matter big time !
I believe you mean average profit divided by subscribers - otherwise you're not really determining anything useful (doing that equation would give me 1.13 subscribers for every dollar I make). Blog Badly earns ~88 cents/subscriber each month.