Some ISPs are in the advertising business to some degree, with DNS redirection and even sometimes direct ad injection. One of the other things the VPN will do,

Some ISPs are in the advertising business to some degree, with DNS redirection and even sometimes direct ad injection. One of the other things the VPN will do, semi-ironically, is prevent this. I suppose Google's philosophy on advertising is similar to how they feel about operating systems: if they can't make money on something, they want to ensure that no one else can, either.