[jhowell]

I tried free trials for both services. I didn't like that they both rely on their own proprietary apps for reading. Oyster's reader appears to be more flexible and their system seems better for book discovery.

Scribd's reader is OK for novels, but I ran in to problems trying to read science and reference books using it. I found that the special characters used in equations were occasionally substituted with incorrect ones and that some tables were incorrectly formatted and links to some footnotes were non-functional. I wouldn't rely on it for anything important. I haven't tested Oyster enough to know if it has similar problems.

I checked both Oyster and Scribd against a large list of books of interest to me, old and new, mostly in the science fiction and fantasy genres. Of those I found 16% books in both services. I also found an additional 5% in Oyster, but not Scribd; and 3% in Scribd, but not Oyster. Most of those books are also available through public library lending services.