If you're happy with your phone service in the US, and you're a moderate or large data user, Google Fi is not likely to be a great deal for you. It's in the price ballpark of other carriers, but it's not cheap.<p>For me, the four major wins for Fi are:<p>1. It's multi-carrier.<p>It seamlessly switches to whichever carrier has the best signal. It also seamlessly switches to VoIP over wifi when in range.<p>You can start a phone call on your work wifi, walk to a coffee shop, and use their wifi, walk home and use your wifi, and while you're walking, it'll hop between cell carriers to get the best signal. While my scenario is a bit artificial, it's impressive.<p>The big win here is that you get a strong signal in places where other carriers fail. I had Sprint in Manhattan, and all you need to do to lose signal is walk next to a tall building. I'd get 5 bars outside my apartment and 2 bars inside. With Fi, I have a great signal everywhere.<p>2. You only pay for what you use.<p>I'm not a huge data user. I never stream media on my phone, and my day-to-day use consists of reading the news and some light Facebook browsing.<p>If you don't use any data, your bill is $20/month. A typical bill for me is about $40/mo, which is about half the price I'd pay with any other major carrier.<p>Sometimes I need more, and having the option is nice. When I was commuting a lot, I'd tether, and use 6-12GB/mo. Since the 6-15GB window is "free", the bill would max out at $80/mo, which is comparable to other providers for similar usage. But instead of paying $80/mo all the time, I only pay that much when I need it. Once, I went over 15GB. The throttling was terribly (256KB), but I was also able to opt-in and pay $10/GB beyond that. I went up to 20GB full-bandwidth for the month, and my bill was $130, but required no commitment. Other providers don't even offer the option.<p>3. There's no commitment. If you own the phone, it's pay-as-you-go. You don't have to commit to a full-year plan.<p>4. The data rate applies internationally.<p>I travel enough that paying $10/mo for data in other countries is a godsend. I used to have to buy local SIMs and pay outrageous rates for data in other countries.