Are the tags user created? One thing I've learned through experience is user created tags are almost universally useless (this is especially true when the service gets popular, and people start adding completely false tags to content, in hopes of garnering more attention).
They're not entirely user created. You need a certain score to add new tags, and by that point you have gotten the feel of Pineapple where I'd trust that user to add new tags. I also moderate all new ones that are added, and update tags for all new resources added. I also delete redundant tags, etc.
