"Be there Day 1," reads a pop-up ad on Howard Stern's official website.

Now that Stern's live show is available for mobile streaming via smartphones -- as of this morning, to be exact -- he appears to be launching an all-out push to get handset owners to embrace the concept of premium radio.

Clicking on the ad on Stern's site opens up a page describing the online premium service, complete with links to all three available platforms: Apple's (Nasdaq: AAPL) iPhone and iPod touch, Research In Motion's (Nasdaq: RIMM) BlackBerry, and Google's (Nasdaq: GOOG) Android.

Stern's site makes a pretty hard sell, leaving me to wonder whether his new five-year deal is loaded with incentives based on how many incremental mobile streaming subscribers Sirius XM Radio (Nasdaq: SIRI) is able to sign up.

That would be a savvy move on Stern's part, especially given the explosion of smartphones in the wireless space.

Stern's pitch won't be a slam-dunk, naturally. In a car, fresh Sirius or XM content is an easy win over commercial-laden terrestrial radio and stale music collections. There still aren't too many drivers fumbling with their smartphones to stream Web-based options, even as more automakers roll out dashboard consoles with all that audiovisual goodness built in. Satellite radio is also largely reliable, unlike the buffering and audio-quality compromises that have set back Pandora and its peers when used on the go.

However, mobile streaming positions Sirius and XM on a level playing field with free or nearly free content. It will be hard to draw a large audience of new subscribers at $13 a month, though the $2.99 monthly rate for active receiver-based subscribers is far more feasible. Now that Stern's on board, Sirius XM should experience a healthy uptick on the cheaper plans for existing Sirius listeners.

We don't know the exact terms of Stern's new deal, but if it's the catalyst for jump-starting mobile streaming plans, it will be provide more reason for Sirius XM shareholders to be relieved that the network's biggest star didn't head elsewhere.

Can premium radio work for smartphone owners who are already paying for data? Share your thoughts in the comment box below.