Chris is redesigning WFG from the top down, and one of the things he's trying to include is reader participation. Here's the background: we've got a lot of new listings coming our way, and if digital writing continues to increase in popularity we believe there will come a time where we'll be swamped by new listings.Chris has said as much over here. Also, I've talked (on Novelr) about how we'd like more new readers - as opposed to fellow writers who read our works - and this is one of the ways we can do that.
My opinion is that readers are currently not signing up (and therefore not rating anything) because there're no incentives for them to do so. The chief value they get from WFG are the reviews, and you don't need to sign up for anything to read a review and find something you want to read. I believe we can get readers to sign up if we provide reader-centric things that come with membership - for instance, the shelf idea, or perhaps widgets to display on their personal blogs what piece of online fiction they're currently reading.
Here's my question: what new features will you, as a reader, think will provide enough incentive for you to sign up to WFG?