NEW YORK ( TheStreet) -- What will be the most powerful tablet advertisement this summer? It could very well be Sprint Nextel's ( S) promotions for Research In Motion's ( RIMM) BlackBerry PlayBook tablet running on Clearwire's ( CLWR) 4G WiMax network. Why? Because Sprint is the only wireless broadband carrier offering unlimited 4G consumption for a fixed price.Jim Cramer has correctly made the observation that TV/movie consumption is rapidly moving in the direction of watching Netflix ( NFLX) on the Apple ( AAPL) iPad. This is true, but unless you are on WiFi, watching Netflix on the iPad can also be a costly proposition. AT&T ( T) offers a 2 gig per month iPad 3G plan for $25, which is rapidly consumed if you use Netflix frequently. The real monthly cost could be a lot higher than $25, as you consume a lot more than 2 gig per month. Here is where Research In Motion's pathbreaking deal with Sprint comes in: So far it looks to be the only iPad competitor offering unlimited 4G use for a reasonable fixed price. We don't have the pricing details yet, but all indications are that it will be very competitive with AT&T, Verizon ( VZ) and T-Mobile -- with one critical exception: unlimited use. This means you can watch as much Netflix as you want, without worrying about overages. Obviously, it is eminently possible that Apple's and Google's ( GOOG) hardware partners -- such as Samsung, LG, Motorola ( MOT), HTC, Dell ( DELL), Lenovo and others -- will copy this deal with Sprint, but until they do, it appears that RIM has taken this bull by the horns and launched the first strike. In fact, I wrote on Nov. 4 that Apple should cut its next deal with Sprint/Clearwire. Who are the other winners in this equation? Sprint owns approximately 50% of Clearwire, which has the WiMax network offering this unmatched 4G capacity and performance. No other operator has 120 MHz worth of 4G spectrum (Verizon has 30 MHz and AT&T perhaps even less). I wrote on Sept. 28, 2010, that it was most likely Texas Instruments ( TXN) that supplies RIM with the PlayBook's dual-core CPU. Who makes the baseband radio chips for the RIM PlayBook? Clearly, the EVDO radio, to the extent that it contains one of those (most likely), is made by Qualcomm ( QCOM). The WiMax radio is most likely made by Broadcom ( BRCM). Why Broadcom? Broadcom has approximately 90% market share inside the end-user devices operating on the Sprint/Clearwire WiMax network, so that's a fair guess, although not totally without uncertainty.