Coke tastes better if you know it's a Coke. That's what a top-notch advertising department does for you. Well, that and early memories of drinking Coca-Cola on a warm summer night. It's the real thing, baby.

Put crudely, name and brand recognition. People view familiar things more favorably than unfamiliar things. If you've heard of it, you are more likely to buy it. If it has been on TV a lot, you've heard of it -- even if you didn't like the ad.

There's a correlation between TV advertising and increased sales over the long term.

http://adage.com/article/media/study-affirms-long-term-sales...

(The favorability thing has been lab-tested by showing people subliminal adverts, among other things.)

Building common knowledge of what choosing particular brands means. If you know everyone has seen those ads with some folks relaxing on a beach with a Corona, then you know that people will think you are laid-back when you bring Corona to a party.

This is why super bowl ads are more expensive per viewer, because the audience can expect their social group to have also seen the ads.