I can drink a glass of water and forget about it. Water is a commodity. Email is not a commodity. If you use gmail, that becomes your online identity. It's har

I can drink a glass of water and forget about it. Water is a commodity. Email is not a commodity. If you use gmail, that becomes your online identity. It's hard to switch. If you use your own domain, you can switch providers without changing addresses, though not without hassle. But switching away from that gmail.com address? It's more than just giving out a new address -- I'm sure that in 1 year, I'll still be getting email at gmail. So that's the difference. With email, you need to plan way ahead. With water, you don't.