@amcain I used VenueWidget to add Foursquare to some of the pages I manage. I have used Woobox to create custom tabs for other pages. I haven’t done a tab that is solely to promote to other social media though. For most of the businesses I manage, our primary network and focus is Facebook over Twitter and Google+ so we try to drive to Facebook from those platforms. We use Foursquare check-ins for recruiting events and at our site for students so we promote that network for check-ins only but we found most of our followers on Foursquare were already Facebook fans and followers so it was a layered on network. 

I offer a Facebook coupon service that requires visitors to “like” your offer, and then be sent to your website, Facebook page or anywhere you like. Here’s a list of past and current offers for your review. Once someone likes it, it shows up on their home page and in their friends news feed. A friend see that you like something and they can click the link where it requires them to like it, where the process starts again.