I wouldn't say 'useless'.Calls made on message boards, on the other hand, unless they're made in advance, are useless.
They're good for spotting who are the good traders and who you should pay attention too.
Calls in advance are fine, too (but you need to actually say ''Will go LONG at xxxx''.
Some people seem to want to claim credit for a 'call' when there didn't seem to actually be one)