Junkymonkey:
Ongoing support for a product is built into the cost of the product. In terms of apps, samsung maintains a platform for other people's apps, as referenced here plex. In the past since electronic devices and software existed you'd buy them and they'd be patched on an ongoing basis, the cost of that was ostensibly built in to the cost of the product. Netgear may patch its routers, but they don't put ads on your internet. Just as Windows would be updated ongoing without slipping ads into the OS. You buy a smartphone, those are updated a few times without additional ads being placed through them by the manufacturer that intrude on other apps.
I would say that if netflix, hulu, hbo, or plex got wind that samsung was putting unauthorized ads on their apps, those guys would pull their apps from those platforms.
That being said, if it's a bug, then what likely is the reason is much like google and apple have ad platforms that app makers can utilize within their apps for revenue thats likely split somehow between the apmaker and the device maker, samsung is creating a tv ad platform that app makers for their platform to use.