Can Anyone Explain This “Adding Clamato to Beer” Thing to Me?

I've been in North Dakota now for about three weeks and I absolutely love it. There is so much going on in Bismarck, so many great things to do, and so many great people...it's really exciting to be a part of. However, there is one thing I don't understand...And that's why everyone adds clamato to their beer?!

I'm a big beer drinker. I love trying out new beers and I'm excited to find something I haven't tried before. Since I've been in Bismarck, I've spent my fair share of weekends sitting at the Blarney Stone, the Lodge, Buffalo Wild Wings, etc. and everywhere I've gone...I've seen people put a big ol' shot of Clamato into their beer. What is the purpose? How did this begin? Why?!

I've asked two bartenders and both of them didn't really have an explanation, except to say that everyone absolutely loves it. One bartender told me that they go through almost two cases of Clamato a day! TWO CASES. Mind-boggling.

Please...someone...somewhere...Explain this to me. I haven't tried it yet but I'm almost to the point where I feel obligated to...But I need answers first.