Earlier quoted context omitted.
Why do you think money wasn't a factor? Foursquare raised significantly more than Gowalla (according to Crunchbase, $71m vs $10m), and as a result grew a much larger team and presumably spent a lot more on marketing.
Actually, until mid-2010, Gowalla raised more money, earlier, than foursquare did. By then, the "check-in wars" were pretty much over. Per Crunchbase[1][2]: In 2008, Gowalla raised $2m, foursquare raised nothing. In 2009, Gowalla raised $8.29m, foursquare raised $1.35m. In 2010, Gowalla raised nothing, foursquare raised $20m. But by the time this happened (June 2010), the "check-in wars" were over (e.g., see: http://…
That's really interesting, I didn't know that.