I think so. If I sell motorcycles and I only have enough budget to show ads to one cohort and have two options:
A) a person who likes motorcycles but has no / very few friends who like motorcycles (presumably a diverse group)
B) a person who likes motorcycles and all their friends like motorcycles (a firm group identity)
I'm picking group B. If I'm successful in selling them a motorcycle, it's free advertising to many more eligible buyers. Plus, even if I'm not there's a chance they might talk about my ad if it's memorable enough and spread via word of mouth.
Teenagers and young were long favored for television advertisements not because of having more of their income disposable or long term loyalty (although nice bonuses) but because they were less set in their ways. And influencing is always what they sold.