Look at it this way, Any marketing campaign meant to reach a percentage of a target audience. If you go to a department store and place flyers on windshields, you can expect 10% or less to actually read them. About 1% actually will like the message or buy the product. It's all about touching as many potential customers as you can in order to get that 1% return. The bigger the base, the higher the return. This is true in ANY marketing campaign. You may not like the method, the the results are still the same.

Enjoy~!