Well, you (commenters) all seem to have some decent insights, but many of you miss some important finer points about the industry, so here’s a relevant primer:

– Apple’s Exclusive: Anyone who says Apple is nuts to offer an exclusive to AT&T is right only on the most superficial level. I mean, duh, it’s better to have more carrier partners, more distribution, more customers. So if that’s the depth of your thinking, it should have occurred to you that you’re missing something. That something is: Apple got a HELL of a deal from AT&T. They got CONTROL, they got to use their iTunes store to move content to a phone, they get a share of recurring revenues. If you know the industry, you would know that this is unprecedented, and it’s something that Nokia, Motorola, or Samsung have NEVER gotten. But you don’t get something for nothing, so Apple had to offer the exclusive to AT&T in return for a boatload of benefits. All in all, it is a great deal for Apple. Without that level of control, the iPhone would have ended up looking like…the Motorola ROKR. That is precisely what happens to a good idea in the era before the iPhone. I’m not sure why 95% of the bloggers and fanboys out there don’t get this.

– AT&T exclusive: it’s funny but while the fanboys wonder why Apple agreed to an exclusive, the telco-heads wonder exactly the opposite: “Why did AT&T give Apple so much control?” And the reason is: this is the first device (ever) that will actually make a customer quit VZW, T-Mo, or Sprint, to move to AT&T. AT&T gave up control in order to compete with the market. I love it. Finally some gutsy competition in the industry. And it’s working.

– Roaming: True that T-Mo runs its own network, as do most of the national cellcos. But that doesn’t mean they run their ‘entire’ network. For example, T-Mobile is relatively weak in California, so they use AT&T towers and base stations for much of their coverage here. Turns out, AT&T uses T-Mo in other places, making a reciprocal deal. The deals these carriers make are not at the 45 cent a minute mark, but much lower…and confidential. In high-density urban areas, carriers will steadily be deploying their own equipment to reduce the roaming usage. So while the concept of MVNO is relatively new, many carriers have been partially MVNOs for some time.

– More Roaming: now, in more rural markets, like Vermont, it doesn’t really make sense for 5 carriers to each deploy a network to cover some farms. Especially in hilly areas where it is more expensive to deploy. Thus, these areas frequently have fewer networks, which then provide roaming to the national carriers. Dobson, mentioned already in the comments, was one of the ‘bigger small’ GSM carriers in the US. Because of a specialized roaming deal, AT&T customers would invisibly shift over to Dobson when in their coverage area, and AT&T would absorb the costs for their nationwide customers. This was an uncomfortable expense national carriers needed to absorb if they wanted to claim national coverage, and put a lot of ink on the coverage map. But companies like Dobson have always known their value in filling out the map, so they charged a relatively high inbound roaming rate – and were also charged the same high rate by AT&T for their regional customers who roamed into the city. This turns out better for small carriers since they end up getting way more inbound roaming revenue than they spent in outbound roaming. What’s more, unlike nationals, regionals often pass their high roaming fees on to the customer, so it doesn’t cost them at all. Sick and tired of these expenses, wealthy nationals are slowly buying up the regional carriers. Dobson just got bought, but you can see Sprint has been buying their affiliates for years.

– More Roaming: There’s roaming, and then there’s roaming. If you take your AT&T phone to Canada, it will likely tell you that you are roaming, and your phone will display “Rogers”, a Canadian GSM carrier. That’s full on roaming, and the charges will show on your bill as roaming use while on the Rogers network. But these US rural roaming deals don’t look that way. The carriers “virtualize” it. For example, an AT&T user roaming onto the Dobson GSM network would never see Dobson on the phone, nor on the bill.

– So it turns out, in the dog eat dog world of business, the regional companies are actually sticking it to the nationals. There is little competition in the markets they serve. They can say to AT&T, “There’s only one GSM network deployed in my region, and I own it. So either you pay me a high roaming rate (expensive), or you can try to build your own (very expensive). Oh..you could also pay me a Billion to sell (not cheap).” Now, I’m not expecting you readers to feel sorry for AT&T, but now at least you can understand why they don’t sell their service in stores in these regions, and don’t want you to buy an iPhone, and take it to these regions.

And, no, Mike didn’t miss the point, he just wasn’t as verbose as I.