The walled gardens built by the mobile network operators continue to crumble. As more and more content can be reached off-deck, mobile users are finding it and the carriers are losing control of their distribution models. With AT&T and Verizon Wireless flinging their networks open, how long before the gardens are gone entirely?

ABI Research conducted a survey to determine where people are getting content for their mobile phones. The results paint an interesting, and evolving, picture. ABI says that today's mobile phone owners use a mix of mobile content obtained from the Web, from their personal collections, and from their wireless carriers.

Some nice statistics:

Video: -- Of the 14% who watch video on their mobile phones, 35% watch free video from sites such as YouTube, 31% watch video offered by their wireless carriers (which they probably pay for), and 28% watch video that they sideloaded themselves. That's a pretty even distribution. Not long ago, no one was watching mobile video from YouTube.

Music: -- Nearly half of music-listening users -- 48% -- get music by ripping their own CDs and sideloading them onto the phone (that's my preferred method). More than one third -- 35% -- buy music directly from their mobile network operator. This is something I have never done, personally.

Games: -- Carriers have a stronger measure of control over where people get their games. Fully 60% of respondents who play mobile games only play the games that were loaded on their phone when they bought it. That leaves 40% to find additional games from other sources, such as the carrier deck, and the mobile Web.

ABI Research director Michael Wolf said, "Perhaps more with the mobile phone than any other electronics device, content is obtained from a variety of sources. This shows that despite the strong control most carriers retain over the network, their control over the mobile content ecosystem remains limited. As the mobile phone grows from being a voice-centric device to a multidimensional communication and entertainment device, content channels will continue to multiply. We expect to see increased content acquisition directly to the phone from the Web. And despite a loosening of control over content delivery, we believe the carriers will ultimately benefit as they open up their networks and handset platforms and look into taking advantage of increased advertising-supported content delivery."

I find it interesting that ABI believes this loss of control will ultimately benefit the carriers. The key for the carriers to retain their revenue streams will be to strike the correct balance of content and advertising delivery.