I already have a family plan with just two lines, and neither line was eligible for an upgrade, so the salesguy told me I could just add a line for $10 per month, and I could buy the Thunderbolt with that new line's discount, then I could just switch the Thunderbolt to my line afterwards, and they said they do it all the time. So I thought, what the heck. I'll do it. This was last Sunday, and they said I should get my phone Tuesday. I didn't get it till Wednesday. Minor annoyance, but not a big deal. Then I activated it to the new line (which apparently you have to do first, before you can put it on whatever line you want.), and after that, I activated an old flip-phone to that new line, de-activating the Thunderbolt. Now I thought, cool I just need to activate the T-Bolt to my number, and I'm good to go. But no. You can't re-assign the sim card to a different number. And since it had already been assigned to the new number, I needed a new sim card. Nobody told me that at the Verizon store. So now it would be another day before I could start using my T-Bolt. The customer service rep said that I just need to swing by a Verizon store and tell them what happened and they will give me a Sim card, for free. So I planned on going by a Verizon store on my lunch break the next day. I did, and they looked at me like I was crazy. They can't just give out a Sim card, they said. It only comes with the Thunderbolt. They had sim cards but they couldn't sell me one or give me one. They told me to call customer service again. I called again, and now customer service is going to ship a new sim card to me. It will be here next monday. lol So now I will have had my T-Bolt a week before I can start really using it. I mean, I have connected to the wifi at my house, and setup my google account, and downloaded a few of my apps. (which was an extremely quick process compared to my Eris), but I can't make calls or texts on it, and I still have to carry my Eris. So anyone planning on upgrading this way, just know that it's not as quick and simple as they make it sound in the store. I think the wifi antenna is better on the Tbolt, because it picked up a strong wifi signal at my house, while my Eris barely picked it up at all.