It's the EXPRESSO that's giving you your burst of energy, the vanilla/latte part is so people that can't handle the strong/manly espresso experience will buy it.

Sort of like people who drink good booze mixed with a sweet soft drink. They want the buzz, but can't handle the taste.

Espresso think Don Corleone, flavored latte think wanna-be.

Yup, times are a changing, but not necessarily for the better, that is unless your Starbucks or another coffee vendor that can persuade someone to pay $$$$ bucks for sweet/creamy morning drinks that a real coffee lover wouldn't be caught dead with. :-? ;D ;D