A few years ago when I used to grind the micro stakes like crazy playing 24 tables at a time and 200k hands a month, it was all about the quantity over the quality.
Your winrates are never going to be great when you play this many tables and put in this many hands. But since I was mostly playing NL25, NL50 and a bit of NL100 on Stars with Supernova, I was making some pretty decent money each month with rakeback alone.