The ease in which it was set up! It's been incredibly easy so far - just login with my Facebook credentials (which are linked directly through Google)and I'm already logged onto foursquare as well; no extra steps or hoops necessary :). There were several things that we needed help understanding at first but after reaching out they helped us straight away :) Great service from start-to-finish really appreciated!! We're using this feature within our own app called 'MyFavourite' where users can keep track of all products added by themselves & those recommended/suggested them when browsing other stores nearby etc.,.