(If you aren't at all bothered by the phrase A third less calories than the regular beer, feel free to skip this post. Most likely it will be lost on you.)
What do the three following corporate slogans have in common?
Live Adventurous. (from Outback Steakhouse)
Think Different. (from Apple)
Yep, each one is eye-burningly ungrammatical. And the more you think about improperly worded slogans, the more examples come to mind:
Winstons taste good like a cigarette should.
Take an Alka-Seltzer and you'll feel better fast.
Of course, the ease with which we remember slogans like these proves grammar can be overrated. The purpose of a corporate slogans is to be memorable. Ungrammatical slogans, while painful to hear or read, are extremely memorable. Keep this in mind when you're selling stuff.
Another point: Budweiser could never use the grammatically correct phrase A third fewer calories than the regular beer. Why correct a memorable and highly effective product slogan to please a tiny sliver of society who would never buy your product anyway?