Several plumes of oil are caught in the deeper water; they are from the leak. They may cause more long-lasting damage than the oil that is carried on the surface.

There is talk on CNN and in the press about a boycott of BP. This would hurt the little franchise holders and their employees more than it would hurt BP.
Moreover, the fuel sold at BP stations may not be from a BP refinery; often deals are made to obtain the gas from whatever refinery is close, additives added according to the buyer's 'recipe'.
For example, I buy from a Shell station convenient to my neighborhood, but the gas is supplied from an Exxon refinery.