I was not here when that happened but It looks at HF 12 had introduced an algorithm which lowers post rewards after the fourth post on the same day.
"Each account can post up to 4 top-level posts per day before a new algorithm will kick in. The new algorithm will start taxing any rewards you earn on additional posts in the same day. Here is a chart that shows how your posting rewards will fall in percentage terms for each additional consecutive post."
It can be easily gamed with multiple account posting, though.
- ta_guy_1
- ta_guy_2
- ta_guy_N
Anyone knows why this is disabled later on?