There's aren't billboards. How about a taste of your own medicine.

Well, I certainly hope that makes you feel better. But, of course, you're wrong (aside from you meaning "these" instead of "there's". The word "billboard" stems from the past where there would be an actual board at the entrance to towns where tradesmen could post their "bills." Not bills like an invoice, but basically advertisements for what they do. thus, the name, "billboard." There are no requirements as to size, and these signs advertise goods and services. What's the problem?