That was.. sort of interesting.
I think a lot of that will fade as they mature, and opt out of bothering.
How many adults bother to go on and "like" their favorite soft drink, or candy? I honestly don't know, but I'd be surprised if these kids kept up their constant "liking" behavior when they grow up a little.
Then again, if a brand can hook them while they're young it may not matter...
There is a lot of hidden marketing though.