I don't believe transfers are possible. I like Aldiko because they have more free books available. Granted, most of them are classics, but nothing wrong with that. Being a mystery/detective nut, I've downloaded a lot of Sherlock Holmes stories, and several others. Some of the mystery books I've never heard of, but they were enjoyable to read. Google Books also has some free books, again, mostly classics. However, so far, they don't even come close to the number of free books Aldiko has.