Msnbc.com and The Weather Channel have added video and and integrated ads into the videos on their mobile sites. The two sites, which are both partially owned by NBC Universal (NYSE: GE), are relying on Transpera to host and deliver the video and advertisements. The ads will be stitched into the content, and range between three and 10 seconds in length. The sites will also be monetized through display banners. The Weather Channel videos, which are already live and can be found at http://mvideo.weather.com, include weather forecasts for 100 U.S. cities, which are updated throughout the day. Starting in March, the videos will go live on Msnbc.com, and be found at mobile.msnbc.com. Videos on msnbc will include clips from “Today,” “NBC Nightly News with Brian Williams,” and “Meet the Press.”

This move is pretty interesting. In the past, it seemed big brand names like these exclusively delivered video in applications because it was easier to know what kind of phone and network the user was on, and could guarantee a certain level of quality. The fact that they are now extending it to mobile sites shows that they are getting more confident about the capability of networks and handsets, and the number of users they are getting—there’s no point in integrating ads if there isn’t the traffic to justify it.