I'm not sure about "Download" and "Play Now" buttons at the top of pages but I usually have "Buy now" ones. Also, they only seem to appear when your are not logged in. I guess the people who provide the facilities for this forum need some kind of income. This is why there is a certain amount of advertising, which you can happily ignore if you wish. I think that there is a way to "hide" it but it is probably more hassle than it is worth.
Fear knocks at the door, knowledge answers and finds nothing.