While I love using the internet and enjoy the rapidly changing dynamic of sites and social media I was reluctant in V1 of dbTwang to consider engineering Facebook Connect into it. Want to reconsider that now and starting by looking up resources to help us make an informed decision.
Here are some of the more useful posts I found.Simple visual guide
This slide show answers some basic questions quickly.http://vizedu.com/2008/12/facebook-connect-explained/
UPDATE: Good list of resources: http://blog.kissmetrics.com/facebook-connect/
Yike - no email address
These two posts address this explicitely - when a new user joins your site using FB Connect you do not get access to the email address they use on FB. This is a deliberate decision by FB and understandable - yet it removes an effective communications medium for the3rd party site owner. The getaround appears to be that you ask the new user for their email once the FB authentication is done.
Update - a reference here to the users real email address being made available to 3rd party sitehttp://stackoverflow.com/questions/1999822/if-facebook-connect-user-changes-email-will-i-be-notified
This is the FB blog notice of this - from Feb 2010 they facilitate the 3rd Party request for a new users email address during the authentication process
The conclusion appears to be yes - implementing Facebook Connect increases conversion rates (signups) and social interaction on a site.Privacy issues explored
If you thought privacy and data ownership was a minefield try tracing the implications when FB Connect is used. My takeaway - there are issues here, somewhere with no clear picture of exactly where or when they will change given Facebooks preoccupation with tweaking those privacy terms and settings.http://www.itbusinessedge.com/cm/community/features/interviews/blog/does-facebook-connect-result-in-shared-ownership-of-data/?cs=34735 http://www.25hoursaday.com/weblog/CommentView.aspx?guid=5332da5a-14a9-4ef0-87a7-5dabcbbf7b11 Beyond new user account signups
Integration using FB Connect means more than just the account set up - you can spread the FB virus throughout your site allowing a new user to find their FB friends who are users of the site or share their site activity back to their FB profile.http://www.simplyzesty.com/facebook/5-services-facebook-connect-effectively/FB Connect - Geek Q&A FB Connect - Rails integration
Welcome additions to this - aware that there must be many more concise and useful resources out there.
My conclusion after a number of hours reading the above - once again Facebook is proving almost impossible to ignore with the scale of returns overwhelming concerns around abdication of core user data to the gorilla in the corner. Bugger.