The perfume ad isn't selling people. Its attracting attention and interest towards the product so that they can go out and check it out. A basic frangrance ad on tv isn't going to sell anyone on the product because no matter what they can't smell it. Gagas ad attracts interest and get people talking about her new perfume so that they may go and test it out and hopefully like it.
I love the ad but so many gays are going to wear this scent now. It'll be obnoxious. At least I'll know which ones to avoid at the club based on their scent now...
Not that I hate Lady Gaga, or even people that like her, but if you wear her perfume... you ain't gettin with me.