LOL, did that in the early days of the phone sex biz. Had sexy biz sized cards made up and we used to put them out everywhere.
We hit an entire mall parking lot once on the car winshield wipers and the malls management company tracked us down and said if we ever did that again they would sue us for everything they could think of until we were buried in legal bills and be forced out of business. I think what happened was the mexicans we had doing it must have put one on the owner's car.
We stopped doing it when the dumb fuckers put some out on cars in a high school parking lot and the next day we got a call from the Distric Attorney's office.
It worked great while it lasted though. Even had guys writing girls names and the numbers with magic markers in bathroom stalls all over. "For a good time call Lisa 976-6969."
So bad, so bad, I know.