ComScore recently released the latest installment of its monthly US Online Video Rankings and there are at least two items of note inside the March numbers.

One, Yahoo’s seemingly out-of-nowhere rise to claim the #2 spot in the Top U.S. Online Video Content Properties Ranked by Unique Video Viewers doesn’t appear to be a fluke. The video portal with an aggressive slate of comedy programming and a shiny new destination website on which to display it overtook VEVO in February to be second only to online video behemoth Google/YouTube on the chart.

The jump up from its previous #3 position in January was due to a massive 20% increase in unique online video viewers (which equated to roughly 8 million individuals) in just one month’s time. That’s newsworthy in and of itself, but what’s even more impressive is Yahoo was able to sustain those numbers. In the last month of Q1 2012 the company garnered 60.6 million uniques, down slightly from its 60.8 million the month prior, but still well ahead of VEVO’s 51.3 million (and well behind Google/YouTube’s 146.1 million).

And two, the average length of an online video is up to 6 minutes and 24 seconds. That clocks in at an increase of 12 seconds month-over-month, 54 seconds over the past six months, and 1 minute 12 seconds year-over-year. If the the runtime of your average online video continues to increase at the same rate (almost 20% per year), it will reach 7 minutes and 26 seconds by March 2013, 22 minutes by March 2013, and a full half-hour by March by 2021.

Hulu’s continual increase in the quantity of programming it offers surely accounts for some of the rise in the length of the average online video, but not all of it. (The internt’s go-to destination for on-demand movies and television shows served 1.01 billion – with a “b” – videos in March 2012. That makes for a more than 200 million video increase in just half-a-year’s time.)

People must be posting videos all around the internet that are all slightly longer than the videos they posted before, which would lead one to think maybe long-form content on the web actually isn’t such a long-shot.

Stopwatch photo by Julian Lim.