Instead of mounting massive frontal assaults, OODA warriors assess the battle as it evolves, using small sorties to gather information and applying force where the enemy is the weakest.
The key to implementing OODA is making sure everyone in the organization understands the mission--schwerpunkt, to use Boyd's favorite Prussian military term--and is given authority to modify tactics on the fly.
If Foursquare can subtly create brand associations and social media product placement in a non-obtrusive way, it may stand a chance, but to do so requires an OODA loop running at a much faster pace with a more diverse view of the marketplace.