My wife recently bet me $5 that I couldn't go through a meal without looking at my phone... I lost. Interesting idea though. They know what sort of atmosphere they would like to have, and they're incentivizing people to make it happen.
I keep my phone in my purse...if I get a notification (email/text), I'll glance at it and act on it only if it's important. If it's a phone call, I'll only answer if it's my mom (who only calls if it's something important) or my husband. Every one else goes to voice mail.