Anecdotal evidence to support that: I bought vCOH after reading a magazine(!) article review but had no interest in competitive multiplayer, and the campaign didn't hold my interest so I stopped playing.
Much later some link to a tournament cast caught my attention and I was so hooked by the action and (importantly) the commentary explaining it that I bought OF and dove into multiplayer, then COH2 when released, bought skins, etc.
