Well the fan riffing board was started before iRiffs even existed. I've posted in both a few times when I've put out a new riff, but I haven't seen much difference between when I do and when I don't. If anything I think the fan riffing board is best used if you're putting out a free riff or selling it through a system other than iRiffs, like some of Quiptracks' work. If there's a forum reader interested in fan riffs, I gotta think they'd check the iRiff board too.