The Advanced Book Exchange was the first big online database for online booksellers in the 1990s. Its major competitor was Bibliofind, which was bought by Amazon. ABE says it has about 13,000 members with 70 million listings and 1.5 million registered buyers.

Just five years ago, more than 90 percent of online booksellers were ABE members. But with the advent of Amazon Marketplace, ABE now appears to control less than 25 percent of today