So far in 2011, foursquare is adding users at the pace of roughly 1 million every six weeks, but co-founder and CEO Dennis Crowley is working toward picking up that pace.

Speaking at the 140 Characters Conference at the 92nd Street Y in New York, Crowley said foursquare introduced its Explore feature so that the location-based mobile app could also function as a city guide, potentially attracting users who would log on to gather recommendations, and not necessarily to interact with other users, The New York Observer’s Betabeat reported.

Crowley cited research from Sysmos, saying that 5 percent of Twitter users account for 75 percent of its activity, and that 21 percent of Twitter users have never tweeted, while 85 percent tweet less than once per day, according to Betabeat.