It may have taken a little longer than planned—and a lot more tweaks—but the Odyl-powered social media tool for book discovery, Riffle, had a quiet launch earlier this week. Originally slated to go live late last year, the once invitation-only site delayed opening until it was populated with plenty of book lists, according to Odyl founder and CEO Neil Baptista. To do that, Riffle added editors in each of 23 categories, from Art/Design to Green Living and YA, to help guide the content and to find bloggers, a thousand of them, who use Twitter and Facebook to push their content and Riffle to list their books.

Many of the adjustments that Riffle made, and is in the process of making, grew out of requests for invitations to join in late March when Amazon announced that it would purchase Goodreads. Trying to fill the gap left by Goodreads for independent users has also caused other changes, including a reversal by Riffle, which had originally planned to avoid reviews and ratings. “Goodreads did a good job of letting people take their data with them. It allows you to export to Excel,” says Baptista, who is in the midst of building a way for Riffle-users to import that information into Riffle within the next month and for all users to add reviews and ratings.

To capture more mobile Facebook users who go from the social media site to another site and then back again, Riffle has also dropped its invitation-only feature. Now wannabe Riffle users can simply sign up and people can share reading lists on Riffle with their friends. Even those who haven’t signed up for Riffle can view reading lists. The site is also courting booksellers by collecting zip codes of those who sign on and then automatically setting them up to follow their local bookstore. “We think handselling is better than an algorithm, and we want to do that online,” says Baptista, who is trying to bring together local with the Internet. He would like to see bookstores list their window and front table displays on Riffle and direct customers to them from their Facebook page.

One thing that has stayed the same is creating a Twitter and Pinterest-like system where Riffle users can follow others. In fact the similarities with Twitter are so strong that people can sign up using either their Twitter or Facebook account. Although Odyl is a Preferred Facebook Marketing Developer and has built Facebook promotions for the big six publishers as well as dozens of smaller ones, Riffle is currently in the midst of a Twitter promotion that involves reading and annotating The Great Gatsby in the run up to the release of the movie, #rifflegatsby. Even the Food/Cookbooks editor has gotten involved with tweets about cocktail recipes and cookbooks from the era.