Now, that figure includes sales made abroad, so we don’t yet know how many were sold by AT&T (T), but it’s clear that the number was substantial. In its third quarter last year, AT&T activated 2.4 million iPhones and 40 percent of those were for subscribers who switched from other carriers. So the fact that Apple (AAPL) sold as many iPhones as it did in the company’s most recent quarter, bodes well for the carrier.

As Craig Moffett over at Bernstein Research notes, “It is entirely conceivable that AT&T’s iPhone alone will account for more than 100 percent of the entire industry’s post-paid subscriber growth in the third quarter.”

But therein lies the rub. For while sales of Apple’s handset remain strong, the heavy subsidies it requires have pushed AT&T’s wireless margins down. And the heavy data traffic associated with the handset have led to widespread complaints about AT&T’s network, forcing infrastructure upgrades. Worse, AT&T’s dependence on iPhone exclusivity at a time when Apple is clearly transitioning away from such a model leaves it quite vulnerable.

“While the strong sales of the iPhone are positive for AT&T in the near term, they increase the company’s reliance on a product for which we do not believe it will be able to maintain exclusivity,” Pali Research analyst Walter Piecyk wrote in a note to clients Tuesday. “We believe more than one third of AT&T’s post paid customer base is tied to an iPhone user and that mix is likely to rise significantly over the next few quarters.”

But not this quarter. This quarter, AT&T is expected to add 1.5 million to 1.7 million net wireless customers, driven by demand for the iPhone 3GS, which was released early on in the quarter. And while another drop in wireline customers is likely to weigh on results, it will be tempered once again by the iPhone. AT&T is expected to earn 50 cents a share, compared to 55 cents in the year-earlier third quarter, according to analysts polled by Thomson Reuters, who see revenue falling to $30.9 billion from $31.3 billion.

Now, that’s still a trifling number when compared to the 50,000 or so available in Apple’s (AAPL) iTunes App Store, but it’s something, and it shows that Palm (PALM) is managing to convince iPhone-addled developers that writing WebOS applications will be lucrative business.

Among the latest and most promising of those new apps, DirecTV’s (DTV) NFL Sunday Ticket. Though the app–which allows users to watch NFL games on their cellphones–is available for the iPhone as well as for the Pre, it may offer a better experience on the latter, as Pali Research analyst Walter Piecyk notes in a research alert this morning.

“We will be interested to see how this application performs on Sprint’s (S) network compared to how it will perform on the iPhone on AT&T’s (T) network,” Piecyk writes. “Sprint is more likely to allow a less compressed stream and therefore higher quality video on its network as we have seen with Sprint’s implementation of YouTube, which is much higher quality than viewing YouTube clips on the iPhone over the AT&T network. When the iPhone is forced to WiFi, the quality of the YouTube clips improves to the level we experience on the Palm Pre but that kind of defeats the purpose of the mobile internet.”

An interesting point and an interesting potential selling point for Palm and Sprint–especially given the beating AT&T’s network has been taking in the media lately.

“Advertising for the product has increased with a more direct attack on the iPhone but that does not appear to have materially impacted sales from its prior sales levels,” Piecyk writes in a note to clients today. “The Pre continues to add applications that will increase the appeal of the phones like Spades and Bubbles, two game applications and total application downloads have now topped 3 million.

“However,” Piecyk adds, “with only 41 apps available we wonder how apps with limited appeal like Shabat Shalom, which allow users to check candle lighting times, are showing up before proven iPhone successes like a basic fart sound application or Facebook.”

Piecyk goes on to suggest that Sprint (S) needs to step up its efforts to market the Pre lest it fumble the best opportunity to come its way in a while.

“Overall the launch of the Pre has been a success for Sprint by increasing the profile of the company’s data network and its use as an effective retention tool. However, we expect Verizon to heavily market whatever WebOS phone they get their hands on. 

“This is a good operating system,” Piecyk notes, “and phone and the multi-tasking functionality is a clear differentiated advantage but competitive advantages in technology are fleeting and we cant imagine that Apple and others will not be able to replicate the multi-tasking functionality in short order. Between Verizon’s launch of a Palm product in 2010 and the inevitable end of the multi-tasking differentiation we believe Sprint is wasting a valuable opportunity to get the Pre in as many customers’ hands as possible this year.”

And just how should Sprint maximize that opportunity? Simple, says Piecyk: Slash the Pre’s price to $99, or even 99 cents.

“We still have a backlog of subscribers but it’s not unmanageable and we get shipments every week. We’ll be short for a while but we’re catching up.”

– Sprint Nextel CFO Bob Brust, June 24, 2009

[This post was updated at 12:36 with comment from Sprint.]

Sprint best step up its marketing efforts for the Pre because according to Pali Research, demand for Palm’s new device is slowing, and quickly.

During the week ending June 26, Pali estimates that Sprint sold 50,000-60,000 Pre handsets. In the weeks that followed, Sprint sold “less than 40,000,” and then, “over 30,000”–again, according to Pali. Now the research outfit says Pre sales have declined by another 5,000 units.

“We really aren’t sure what Sprint is waiting for in stepping up the ad campaign but Palm Pre sales have continued to slow over the past two weeks and we believe Sprint is currently selling roughly 25,000 per week, down from over 30,000 two weeks ago and over 50,000 in late June,” Pali analyst Walter Piecyk said in a research note this morning. “Advertising could increase in the coming weeks but we are headed into August and there is a new BlackBerry now vying for the attention of wireless customers.”

And don’t forget that $99 Apple iPhone 3G.

Piecyk concludes by suggesting that Sprint (S), by failing to market the hell out of the Pre, is fumbling the best opportunity to come its way in a while.

“Slowing sales cannot be helping CEO Dan Hesse’s ability to extend the exclusive period for the Pre as Palm (PALM) likely views a Verizon launch as something that could materially stimulate sales,” Piecyk said.

“Hesse has never been one to resort to price cuts but we wonder if dropping the Pre to $99 could reignite sales,” the analyst continued. “…Sprint’s future is certainly not tied to the Pre but this is a great product that could highlight their data network. We believe they are squandering this opportunity over the past few weeks. Sprint is still not in a strong enough position to let good opportunities pass them by.”

And what does Sprint think of that assessment? Not much. Reached for comment, a spokesperson told me: “we are very pleased with the performance of the Pre and the excitement it’s drawn; we are selling all the quantities that are being delivered to us and we are ramping up advertising this month — did you see the full-page ads this week comparing the value and performance of the Pre to the iPhone? — and we are expanding availability of the handset at Best Buy, Radio Shack and online, with future expansion of availability planned. As Dan Hesse noted in California today, it takes a number of months — through a whole ramped-up sales cycle — to determine the real performance of a handset in the marketplace. Folks like to speculate and toss around ideas on the internet all the time, but the truth is Sprint is very happy with how the Pre is doing.”

Today brings another Palm-related research note, this one from Pacific Crest analyst James Faucette. He claims that Pre sales are “robust.” According to Faucette’s channel checks, Palm is selling about 40,000 Pres per week, a “normalized” sell-through rate that he says will continue through August.

So who’s right? Piecyk or Faucette? Who knows? Until Palm (PALM) and Sprint (S) go on record with real sales metrics, we’ll have to use our imaginations. Which is pretty much what all these analysts appear to be doing right now, anyway. Honestly, they might as well be issuing research notes on jelly bean jar guessing games.

Oh, and for what it’s worth, Palm and Sprint are not willing to release sales numbers right now. Reached for comment, Sprint told me, “We’re excited by the response to Palm Pre. Demand continues to be strong, and we are working closely with our partners at Palm to meet the needs of every customer as quickly as possible.” And Palm told me me to call Sprint…

“We estimate that sales of the Palm Pre slowed again over the past week compared to the prior week but likely remain over 30,000 compared to less than 40,000 in the prior week and our estimate of 50,000-60,000 in the week ending June 26th,” Pali analyst Walter Piecyk said in a research note this morning.

Now, to be fair, the holiday weekend may have negatively affected sales. And another report from Piper Jaffray suggests that the Pre is cutting into sales of RIM’s Blackberry. So there’s that. Still, if Pali’s estimates are correct, it’s pretty clear that demand is tapering off a bit.

Perhaps it’s time to ramp up the Pre’s marketing. Problem is, marketing costs money and Palm doesn’t have very much of that right now.

“You know the beautiful thing: June 29, 2009, is the two-year anniversary of the first shipment of the iPhone. Not one of those people will still be using an iPhone a month later.”

– Palm investor Roger McNamee

Palm (PALM) seems to have satiated pent-up early demand for its new Pre smartphone, constrained supplies be damned. In a pair of investor notes issued today, analysts at Pali Research and JP Morgan say that sales of the Pre have tapered off to a point where supply and demand are roughly in parity.

“We have concluded our 3rd round of channel checks for the Pre,” writes JP Morgan analyst Paul Coster, who notes that demand for the handset is hovering at about 40,000 per week. “The gap between supply and demand has closed at Sprint and BestBuy stores, waitlists are eliminated or down, and most stores now have Pre devices in stock.”

Pali Research analyst Walter Piecyk also surveyed the Pre landscape and reached a similar conclusion, though he sees the slowing of sales as a bit more pronounced. “We believe that Palm Pre sales have slowed over the past week for Sprint to under 40,000 from 50,000-60,000 last week,” he writes. “…We suspect that if sales continue to moderate, Sprint would increase its marketing budget for the product. The marketing budget behind the product has been somewhat limited to date compared to the marketing push that Apple does.”

Indeed. And let’s not forget that Apple (AAPL) has a new handset on the market that’s been selling quite well. Makes you wonder if this ebb in demand for the Pre is somehow related.

Guess it’s looking like Palm investor Roger McNamee’s hyperbolic predictions about iPhone-to-Pre conversion aren’t going to quite pan out.