I was talking with Jeremy (the brains behind Booktagger) about what kind of features an online bookstore could have to help affiliates do a better job. After documenting some, I thought they might make an interesting blog post. So, good features for a book site to have, to help affiliates do a better job:

1) An API.  The API should accept two types of query – ISBN and a text based search. They could be separate URLs or they could be combined into a single URL and just intelligently recognise if an ISBN or search string has been submitted.
1a) If an ISBN has been submitted, return an XML formatted document including ISBN, title, author, publisher, format, availability, link to cover image and price.  If the ISBN isn’t found, return an XML document explaining that there were 0 matching records.
1b) If a search term has been submitted, do a search and return a list of matching items.  The items could either be complete – multiple records of the type above in 1a, or an abridged version, requiring the user to resubmit the individual ISBN to get a detailed version of the book.

2) A method of allowing an affiliate to add multiple items to a users carts.  To see an example of this, add a few books to Booko’s cart – make sure the books are all available at one of the sites which include this functionality such as the Nile or an Amazon. Once you’ve added a few items, click the “the Nile” or “Amazon ..” link in the cart and you’ll be taken to a page where you confirm that you’d like to add all the following items.

3) Easy to read and generate links to books which can be created based on the ISBN. Like, http://site.com/books/isbn/123123123.php

4) An Affiliate program.  The affiliate program should make it easy to create dynamic links to any book in store. Perhaps within the URL or as an argument ?refid=123 style.

These features would make it a book store easy to work with, and helps the end user’s experience by integrating the shopping carts.