Comcast Corp. will try to amp up video-on-demand (VoD) usage with "Watchathon Week," a promo that will deliver a self-described "free pass" to more than 3,500 TV episodes from 30 programming partners on set-tops, smartphones, tablets and PCs.

During the promo, set to run from March 25-31, Comcast will give video customers access to the full VoD libraries of HBO, Showtime, Starz and Cinemax, whether they subscribe to those premium services or not. Comcast will follow with "Catch-Up of the Week" on April 1, offering a mix of current and past seasons of hit shows on a specific network or different, popular TV series each week through the end of the year. (See Comcast Plans to Pump Up VoD Usage and Comcast Sets VoD Watchathon Details.)

Xfinity TV customers with access to Comcast's VoD service are eligible for Watchathon Week, so that means the vast majority of its 21.25 million digital video customers will be able to partake in the VoD-fest.

Giving an apparent nod to a model/trend that's been popularized by Netflix Inc., Comcast's Watchathon will target "binge viewers" who want to dig into and get immersed by a new series or just simply catch up on one.

There are some obvious motivations here. The promo will give customers a taste of premium services in the hopes that they'll sign on. It should likewise encourage overall usage to spike, which Comcast will want to see happen as it continues to roll out dynamic ad insertion, a key piece that will help the company make money on all that "free" VoD fare.

Here are the numbers to be thinking about once Comcast begins to share the results of its VoD promo: Comcast customers are already watching more than 80 million hours per month in TV shows. With movies and other types of VoD content tacked on, Comcast streamed out 2.4 billion hours of VoD in 2012, up from 2.1 billion in 2011. (See Time To Teach Old STBs Some New Tricks.)

If you're looking for where the bar is currently set, Netflix's 33 million global subscribers are viewing more than 1 billion TV shows and movies per month.

— Jeff Baumgartner, Site Editor, Light Reading Cable