Portals play the affiliate game too. Up to half the space on a portal front page may be taken up by affiliates and adverts. Most visitors will ignore them after a couple of visits. From then on, they become a constant reminder that the aims of the portal and the aims of the visitor are not the same. It's all a matter of degree.
Most Web users are aware that advertising and affiliate programs pay the rent.
In most cases they accept a touch of commercialism with good grace. As they become increasingly familiar with the Web, they attempt to ignore banner ads, which then become subliminal and therefore work in a different way. It's when commercialism becomes intrusive that it spoils the party - when it becomes commercial overkill. There's barely any money to be made in this sector and heavy commercialism is rife. Many sites offering these services appear to think their webmaster visitors are fundamentally dumb and highly susceptible to garish hype.