Yes and no. They know they're making a spectacle of themselves which garners the media's attention, meaning they get free publicity. However, my point is that they do not actively go around looking to buy any sort of promotional . They wait until the media comes to them and they usually do so without fail.
This is exactly the type of attitude they feed upon. They enjoy being reviled and loathed by all these Christians claiming to espouse God's love while spouting off every insult they can think of at the WBC. It seems to be a highly effective strategy from what I can tell. (By the way, Shirley Phelps-Roper is Fred Phelps' daughter, not his wife)