The laundry detergent on TV is the famous laundry detergent, just like the actor on TV is the famous one. Branding is really trying to turn the thing you're selling into a cultural icon.
People don't goto football games to watch the Goodyear blimp.
People never ask to be advertised to but..,
Where people go in mass, advertisers want to reach them.
There is no place people go consistently more than Facebook and they have the best mechanism for targeting so many niche sets of users.
And to argue facebook isn't culturally relevant vs TV. I'm a little bit lost with that one. Memes and videos everyone must watch are a cultural phenomenon heavily driven by Facebook.
The fact that Facebook advertising targets you so well (or not) is something that is a common conversation just like talking about the annoying (or not) commercials that exist on TV.