And that bottleneck is … advertising. While developers and publishers have evolved to support a digital video eco-system, advertisers are a step behind. The problem is common to all sorts of media transitions: the impulse to replicate old experiences on new platforms.

YouTube’s director of product management, Shiva Rajaraman, summed up the situation at this week’s Mobilize conference. Rajaraman explained that many conventional constrains of video advertising — especially the 15 or 30 second time limits — are artificial and dictated by the strictures of traditional TV. But in the online digital environment, many of those conventions don’t apply and there is endless opportunity for new types of creative ads.

Ad agencies, however, have been slow to pick up the ball, according to Matt Minoff, the CEO of Selectable Media. Minoff’s company makes a business of dropping short video ads into places where viewers might encounter a paywall or an offer to buy something. In practice, this might means that a video game player can receive virtual goods in exchange for watching a video. The player might see a screen like this:

If the player wants to earn the virtual cash, they can choose from a variety of videos:

After watching the video, the viewer receives a benefit such as virtual goods credit or access to an article. Minoff says publishers are embracing the ads and viewers are willing to watch them. His company is profitable and growing but he says appropriate ads are in short supply.

“What holds back advertisers from taking advantage of new platforms is that have to repurpose creative built for TV. They’re utilizing 30 second TV spots online and for mobile.”

Minoff believes that ad agencies should consider reallocating their budgets to create more custom content for online platforms. While this would take a larger investment into creative, the potential pay-off could be large if it improves advertisers’ ability to deliver the rights ads in the right situation.

(Image by Jacek Chabraszewski via Shutterstock)

Shiva Rajaraman, YouTube’s director of product management, joined our video reporter Janko Roettgers at GigaOM’s Mobilize conference to explain the company’s view of mobile.

Screens are everywhere, Pages are dead

According to Rajaraman, 25 percent of YouTube videos are being watched on mobile devices and the number is accelerating rapidly. In some markets, like Korea, that figure is already at 50 percent. Rajaraman attributes this rise to everything from larger screen sizes, more 3G and 4G networks, and consumers turning to tablets over desktops for info and entertainment.

For content makers, this means that creating a video channel page in a “classically desktop” design is folly. Pages with links, browser bars and other desktop architecture just doesn’t belong in a video environment, says Rararaman.

“Pages are dead,” he says. “It’s all about fluidity and a full screen model.. like TV.”

This means that YouTube’s partners have had to adjust to how their content is presented — and where it appears. While the site once let video makers publish to discrete devices, now their only choice for syndication is monetized or non-monetized platforms. The reason for this is that YouTube wanted to put a stop to the “odd experience” where a video shared from a desktop can’t be seen on a mobile device. Rajaraman said the channels must be everywhere in the same way that your friends are always there on a social network no matter which platform you use.

But what about monetization?

Unlike display ads, which have proved a rocky fit on smaller screens, video ads have made a smoother transition. Rajaraman says that YouTube’s plan is to continue scaling its skippable pre-roll ads across all devices where people watch them as part of a fluid package of content.

He also noted that while the format of online video resembles TV, the advertising environment is much less restriced. Ad makers are not constrained by artificial 15 or 30 second windows and that the possibilities for execution are much broader. Rajaraman observes, for instance, that advertisers trying to induce a call to action (like asking a viewer to go to a web page) can try to reach the target with one big splash rather than using conventional TVs tactic of bombarding the target with the same ad.

Audience members asked if the video ecosystem is threatened by phone carriers’ increasingly strict limits on data usage. Rajaraman said that YouTube was looking for ways to “uncap” people but that the company for now is not disclosing how much content is consumed on Wi-Fi versus on phone networks.

He also suggested that YouTube was in the process of developing something analogous to Apple Airplay for Android.

On the broader picture of how consumers will interact with video content in the future, Rajaraman said that TV will be used for display and mobile devices for discovery.

Check out the rest of our Mobilize 2012 coverage here, and the live stream can be found here.

At GigaOM’s Mobilize conference in San Francisco on Thursday, Jack Buser, Sony’s senior director of PlayStation digital platforms, talked about why Sony developed the PlayStation Mobile platform for PlayStation games that can, for the first time, be played on devices not made by the Japanese company. The short answer to that is basically that they had to: Sony had to reach gamers on the devices they are already using.

“We embraced PlayStation Mobile because we know there are situations where gamers may only have their mobile device and we want to supply a PlayStation experience no matter what,” Buser said.

That list of devices includes smartphones and tablets made by HTC, Fujitsu and Sharp, among others. The theme? They’re all Android-based devices.

The benefit to participants is free marketing. For Android game makers that want to build for the PlayStation Mobile platform — which will play games on the PlayStation Vita as well as PlayStation-certified mobile devices — Sony will use all the marketing heft it has behind its multiple gaming channels to advertise and promote those games.

Recognizing the role of mobile, and that people are used to paying 99 cents and not $49.99 for games, Sony is rolling out a mobile subscription gaming plan too. PlayStation Plus is a subscription service for the PS3 and PS Vita. Five dollars per month delivers a new set of games to the user. They’ll be big titles, too, he promised. Not many casual games.

Sony is promoting “console games for console gamers,” Buser said, likely referencing mobile gaming leader Zynga, not “farm simulators.”

Update: This post was corrected at 9:49 a.m. on 9/21 to note that PS Plus is for PS 3 and PS Vita customers. It has not yet been announced whether the service will be available to other PS Mobile devices.