Despite my earlier protests on this blog, I caved in and started using Foursquare. I previously had little interest about advertising where I was or where I was spending money. The former, I figure I could just Tweet when I wanted, and the latter, I still find a bit gauche. However, the tipping point for me was the introduction of coupons and other loyalty deals. Out one night with a friend, she pointed out that the club we frequented offered ...