I noticed a discussion of this titled: How to Get Paid for your Flickr Photos over at Photopreneur.
Marketing the Flickr Way
But to increase the chances of making a sale, you have to market. Like anywhere, it’s not enough to put your goods on offer — however good your photos might be — and hope that photography-lovers with bucketloads of money spot them. You have to let people know they’re there.
On Flickr, that doesn’t mean spending vast sums on pay-per-click advertising.It means investing time in networking.