Comcast has formally announced their version of TV Everywhere is now online.  Fancast XFINITY TV “is available to any Comcast customer with a digital cable and Internet subscription.”  There is no additional charge for the service.

Comcast customers can access the service after logging in through Comcast.net or Fancast.com with their account username and password.  Once “authenticated” as a confirmed Comcast cable subscriber, customers can watch approximately 2,000 hours of programming from more than 30 cable networks, including premium channels HBO, Cinemax, and Starz.  A demonstration showed Comcast had complete seasons of series like The Sopranos and Big Love.

Some programmers are exploring whether Nielsen can count online viewing as part of its ratings measurements.

Initially, Comcast will restrict access to customers who are confirmed digital cable and broadband customers, but will extend the service to those who only subscribe to Comcast cable programming in approximately six months once security and authentication issues have been resolved, according to company officials.

The service should be accessible by subscribers on-the-go through mobile broadband or other connections, as long as customers log in.  Access is not allowed outside of the United States for copyright clearance reasons.

Customers should be aware any video accessed by the service counts against Comcast’s 250GB monthly usage limit.  Advertising on the service also counts.  Unlike Hulu which typically provides just one advertisement for every break, Comcast’s program partners have tested full commercial loads, up to seven minutes worth in a 30-minute program.  That’s 14 ads to sit through, each eating into your usage allowance.  Comcast says programmers are individually testing different amounts of advertising to learn how viewers react.  The prevailing view is that online viewers are less tolerant of advertising than typical television viewers.

It has been a busy week for the TV Everywhere test project.  First, two premium movie networks — HBO and Starz agreed to participate in the trial, and now CBS, the first broadcast television network, today announced it was signing on as well.

CBS will be running a mix of older and current shows as part of the trial with Comcast subscribers, probably including its popular shows like CSI and NCIS, which are already available in some areas online through Comcast’s “Fancast” portal and through Time Warner Cable’s Primetime on Demand channel, available on digital cable.

“CBS and Comcast share the same vision of giving consumers more — more content, in more places,” said Matt Bond, Executive Vice President of Content Acquisition, Comcast Cable.  “On Demand Online is a major step in extending consumers’ television experiences online, and ultimately across platforms by giving any television network, including top brands like CBS, the ability to make their content available on the Web.”

CBS historically has avoided partnerships with the cable industry.  It is the only network that never launched a cable network (ABC Family, MSNBC, CNBC, fX, and others on offer from other networks), and also steered clear of a partnership with Hulu, which has ABC, Fox, and NBC among its partners.

The network is interested in the potential exposure its shows might have on-demand, particularly among younger viewers.  But more importantly, being friendly to the largest cable companies around may prove fruitful when the network wants retransmission consent agreements signed, permitting cable companies to place the network’s owned and operated local TV affiliates on the cable dial without a lot of aggravation and negotiations over fees.

TV Everywhere will offer “authenticated” subscribers to cable television or satellite service access to on-demand, streamed video programming through broadband networks.