Update: ScanScout incorrectly stated that 3 times as many clips were watched a week after the game. The actual ratio is about 1.6 to 1, as seen in the chart above.

Video ad network ScanScout has concluded from analysis of Web video traffic that far more football videos were watched on Sunday, February 14th — one week after the Super Bowl — than on the day of the game. As seen in the chart above, the week-later audience was about 60 percent larger than the Super Sunday crowd online. Altogether, far less than half of all Bowl-related football-watching was done on the 7th.

Of course, the biggest audience was the live one. Super Sunday is effectively an American national holiday. But as a ScanScout spokesman emailed me, “The tried and true methods for TV don’t necessarily apply to online video. The smart move for advertisers coveting the Super Bowl audience is to spend TV ad dollars on game day. Then, switch to online video the following Sunday.”

ScanScout, founded in 2005, is part of the video ad industry based in Boston, although the company maintains offices in New York and Los Angeles. ScanScout has amassed $17.5 million in funding, most recently an $8.5 million round in October 2009 that included EDB Investments from Singapore, plus Time Warner, General Catalyst Partners, and First Round Capital.