Forum Posting Is great Way in Keeping yourself Update with new and old techniques and Getting knowledge and Also Allows you Place your views on Numerous topics . Forum Posting is Say great idea when Thinking for both Earning and Learning .
There number of benefits of forum posting. Most webmasters using it for getting more link juices from other well reputed sites. Some using it for sharing their knowledge with others while some doing it for getting solution of certain query.
I do not think there is limit to forum posting as you are practically are being engaged with people, sharing and receiving new information. It also has an impact on your business or web site as it can drive traffic and possible sales.