Advertisements shown during this week's Superbowl broadcast were inconsistent in their use of online marketing techniques, according to reports.

Writing on the SearchEngineWatch blog, industry insider Chris Boggs noted that while some commercials were clearly driven towards increasing web traffic, some omitted their website addresses completely.

Notable among these, he claims, was the decision by Coca Cola not to feature its company URL on advertisements during the game.

Mr Boggs said: "For those that did display and/or mention URLs, not all actually encouraged the viewers to visit the site."

"Many of the ads that did show URLs displayed them in either a very small font or in an otherwise unmemorable manner," he added.

Some companies were seen by Mr Boggs to display their URL clearly on initial advertisements, but omit them from subsequent shortened versions of the commercial.

Meanwhile, broadcaster CBS rotated the URLs of a number of its websites on screens leading to and from commercial breaks, he claimed.

The marketing potential for the Superbowl may be large as, according to Indiana company Wish TV, this year's event was the third most-watched broadcast in US history.