Advertisements on the iPad? Bring 'Em On.

The 30-second spot didn't always exist. Someone had to invent it. Same goes for the full-page magazine ad, the couple-of-minutes-long movie trailer, and, much more recently, the Google search ad. For an advertising medium to matter, someone has to first come up with a killer format.

Last week in Cupertino, Calif., Apple CEO Steve Jobs unveiled iAd, the equivalent of the 30-second spot for mobile devices. At the time, the announcement was drowned out by fuss over other new features for iPhone OS devices, namely multitasking, but in time this will prove to be the day's big news. Whether you heard details of the iAd platform or not, you really need to see video of it in action:

Click ahead to about the 6:00 mark to see Jobs cue up a Toy Story 3 demo. The ad takes over the screen, and can contain any kind of media—photos, audio, video. So far, nothing new. But these ads can also contain intuitive touch- and tilt-sensitive games. Maps of theaters, zoomed in to your location. Apps within the app. The ability to make purchases within the ad itself, using the credit-card information Apple already has on file. "Have you ever seen a mobile ad like this?" Jobs asked the audience. "Anything even close?"

Some tech pundits were less than enamored. Slate's normally genial Farhad Manjoo penned a sarcastic screed. NEWSWEEK's Dan Lyons thought Apple's creep into yet another big-money industry was like Tony Soprano taking over Disney World.

Yes, yes, it is lamentable that we are inundated with advertising from the moment the radio wakes us up to the time we fall asleep watching Hulu. But c'mon: advertising is a necessary evil. Ads are what will keep many iPhone and iPad apps free, and iAd appears to be an engrossing, elegant way to do it. Some advertising is better than others—people watch the Super Bowl for the commercials, and movie trailers are often better than the films they promote. The Toy Story 3, Nike, and Bed Bath & Beyond ads that Jobs demo'd in Cupertino belong in this superior category. Even though they were simple efforts, dummied up in a limited amount of time, they're engaging—you actually want to interact with them. Compare that with the sorry state of Web advertising. Assuming you don't have ad-blocking software installed, when was the last time you gave more than a glance to a display ad on a Web page? Have you ever felt anything other than exasperation as an "interstitial" prevented you from accessing a news article online? Clearly, there will be a great many annoying iAd ads. (That's going to get tiring to say.) But in a way that the Web has never delivered on, advertising on the iPhone and iPad has the potential to be a fun and engrossing experience.

Not to pick on a fellow magazine, but GQ's iPad app demonstrates why the iAd platform is necessary. The GQ app looks gorgeous, but it's largely just a re-creation of print pages in digital form. Ads are shown exactly as they appear in the magazine. On some of them, a drop-down bar allows you to click over to the advertiser's Web site—not exactly mind-bending functionality. Ads this rudimentary are not going to be what makes magazines money in the new medium. The most obvious missed opportunity is a Gap spread, a static image. Gap has its own interactive iPad app! It's silly that Gap stuff would be vividly interactive on one part of your iPad but dead to the touch on another. IAd bridges this divide.

This is meant to be constructive criticism. GQ is to be applauded for having such an early, promising iPad app, and as soon as iAd goes live, it'll make a lot of money. A part of the media's fascination with the iPad is that this lets us put the horses back in the barn a bit: it lets us make money while producing content in digital form. The iPad won't save publishing in the way some hoped. But iAd can be the foundation of a paid new world.