The money in the long tail is for the aggregators and filters, not for the producers. If you sell hundreds or thousands of products, or show people to way to those products, there is money to be made. The hike in volume you generate for the person making the product might not be all that much though.
Again, while these different filtering technologies may make it slightly more likely that an end user finds his or her way to a piece of obscure content, it will not likely be sufficient to catapult an artist into the mainstream. The beneficiary of the filtering is the end user and the filterer, not the content owner per se.