I've seen quite a great nos of newbies online marketers commiting this mistake while actively promoting products or sites.

These are some key pointers when doing forum posting

-> Most forums have their posting rules and doesn't allow affiliate links in posting. 90% of forums I've seen allows affiliate/promo links only in your signature.

(hint- signature are usually found in profile or account area. look for edit profile or edit signature link. and dont throw in a whole salespage into the sig file area, there are usually charaters limits like 255 depending on forums setting)

-> Quality Forums are not links dump to throw promo links everywhere, look out for particular section where promo ads and blatant affiliate links are allow and post ads only in those section.

-> Include avatar or profile images will make your post easier to locate by users and yourself. Prepare a jpg avatar of size 80x80 pixel and lower than 20kb will ensure a good chance of image being accepted by 90% of forums that allows avatar upload.

-> When posting, write in short sentence and paragraph. the most unreadable posting are one huge chunk of text with no breaks.

Hope by sharing this would help those starting out avoid the pitfalls when participating in forums.

All said, share, enjoy and engage the warm forum community.