One of the most successful marketing campaigns and brand icons in American advertising history by every single measure. So, to answer your question, a lot of people. Far more than don't.

You'll also notice that you see her less often. The Dr. Rick commercials have been a huge hit as well, and there has also been more emphasis placed on the other characters, Flo's "friends." This is to extend the Flo lifecycle as long as possible, because the Flo ad campaign has been such an enormous success.