Before there were exposed social graphs to blast out notifications and invites to, there were social networks that provided this functionality through… wait for it….the Internet.
Perhaps the defining feature of the viral growth that has characterized the social media era is the ability for users to access their email address books via a social network and invite more friends.
A while back I wrote about Plaxo’s free tool that lets web publishers provide this functionality without building it themselves.
Now Rapleaf has released a full address book API that lets you configure this same viral functionality to your site with more flexibility. The API currently supports Gmail, AOL, Hotmail, and Yahoo! mail services.
Rapleaf differentiates its offering from Plaxo as follows:
Plaxo’s Widget works great for people who don’t know how to code. Rapleaf’s Address Book API is great for people who can code and know what a REST-based API is. Additionally, the PHP and Perl client libraries make Rapleaf’s API easy to use for coders with even the most basic skills.
Rapleaf is quietly accumulating an enormous database of consumer interests, friend relationships, and demographics by crawling publicly available information. This information can then be called up by email address, allowing Rapleaf partners to get a pretty robust view of their user bases. An address book API is a logical extension of this core competence.
Sites using the Rapleaf Address Book API include Bitsrips.com and eVelvetRope.

