Microsoft's Subliminal Advertising-I just don't get it!

It started with the Windows Phone and now the Surface RT/Pro. Pretty much any TV program you watch these days, you will see them pull out the Surface device or Windows phone to use. Yet in reality nobody is buying them.  Knowing that any production company will gladly use 'free stuff' for props it is no wonder these devices show up online. But from Microsoft's own perspective on advertising and promotion, really?  I think it would make more sense is placing that money in to research and development and simply getting a good product out there. Then you won't need to flog this crap off on lame TV shows!