> But I don't understand why so many restaurants still hang on to it.

It's cheaper than having to deal with paper that gets dirty, torn apart by kids or outright stolen. And "daily special" doesn't need to be manually inserted into menus any more.

I've mentioned it in another thread about ice cream machines already: restaurants and hospitality in general are absurd cheapskates. Whenever a tiny avenue opens that saves them money, they'll do it, legal or not - the only thing that matters is that it looks acceptable to customers.