I can't understand how OEM:s think it is a good idea to get paid to preinstall trial versions. When I pay for aproduct, I don't want to be treated as their prop

I can't understand how OEM:s think it is a good idea to get paid to preinstall trial versions. When I pay for aproduct, I don't want to be treated as their property to be sold to advertisers. It's the same when I want to watch a movie trailer on the largest cinema chain here in Sweden. I have to watch an ad before I am allowed to watch the ad for the product they sell. It's ridiculous.