• by Wayne Friedman , April 21, 2011

With TV's upfront advertising market only weeks away, Nielsen says a number of key digital trends could be factored into some decision making for marketers -- including online video usage and social media on broadcast sites.

One key indicator: in January, almost half of all U.S. citizens -- 143.9 million -- viewed some video online. Overall, online video viewing came to an average of four hours and 39 minutes for the month. A subset of this is that mobile video viewing is 41% higher than it was a year ago.

Good news for some of the digital broadcast media sites: While social-media usage of Facebook and Twitter keeps growing, Nielsen says in January 2011 alone, 49% of all social networking and blog site visitors also visited TV network and broadcast media sites.

Twitter had the biggest overlap with broadcast media sites at 76%, while Facebook was at 50%.

Looking at the market as a whole, TV advertising continues to grow -- now at $69 billion in 2010, according to Nielsen, up 8% versus the 2009. Of this, $20 billion went into prime-time TV programming, which was up 6% versus a year ago. Prime time accounts for 43% of all TV advertising.

TV advertising is now 57% of all U.S. advertising's $120 billion take -- and growing faster than U.S. advertising overall, which posted a 5.4% hike in 2010 versus 2009.

Time-shifting machines/services are now in 38% of all U.S. TV homes with older 35-49 viewers watching the most -- three hours and 8 minutes a week. The lightest time-shifted viewers are 12- to-17-year-olds at one hour and 31 minutes.

Also, about 46% of Super Bowl viewers in February were female, the same percentage as last year, although the total rose to 51.2 million out of a total audience of 111 million.

The numbers of African-American and Hispanic viewers grew to about 12.5 million and 10 million, respectively.