It’s because they have more disposable income and are more likely to make a splurge purchase on a soda. In the past, those purchases would be a 12 ounce or 16 ounce bottle of soda. In 1994, all of that changed with the upsized 20 ounce bottle that cost a little more. With consumption rates trending in reverse, smaller cans of soda are being offered [at similar 12 ounce can prices] to appeal to the “healthy” choices that people are trying to make. The billions of dollars being spent in marketing seems to be working. A 1% increase in sales doesn’t seem like much, but with a $75 billion industry, that’s $750 million in extra cash.