
Statistics released by web monitoring firm comScore show that American consumers flocked to television, sports and news websites during the month.
The rise was attributed to the start of the new TV and football seasons, in addition to Americans visiting sites remembering the atrocities of 11 September 2001.
Gambling sites also experienced huge gains prior to the move by Congress to outlaw online gambling. Online gambling was the top gaining category in September, recording a 17 percent gain over August.
Leading this category was embattled PartyGaming with 10.9 million US visitors, a 75 percent increase, followed by SportingBet, the second biggest gaining website during the month with 5.4 million US visitors, up 194 percent.
"The move by Congress to outlaw online gambling comes at a prime time for the football season, as people around the country are placing bets on their favourite teams," said Jack Flanagan, executive vice president at comScore Media Metrix.
"As speculation continues about the future of these online gambling sites, fans will very likely continue to turn to fantasy games on traditional sports websites, which also saw big increases last month."
Americans also checked out sports websites in September, triggering a 7 percent increase to the sports category overall.
Leading the category was ESPN with 20.4 million visitors, a 14 percent increase over August, followed by Yahoo Sports with 17.5 million visitors (up 27 percent) and Fox Sports on MSN with 16.5 million visitors (up 25 percent).
Despite heightened interest in Major League Baseball during September as the teams jockeyed for playoff position, traffic to MLB.com fell 16 percent compared with August to 9.1 million.
As the new American television season started, sites dedicated to specific hit shows drove overall traffic to network TV sites.
ABC.com experienced a 78 percent increase to 8.1 million visitors, driven largely by traffic to the Dancing with the Stars site, which saw a 212 percent increase to 826,000 visitors, and Grey's Anatomy, which saw a 206 percent increase to 679,000 visitors.
NBC Network sites also saw a notable gain of 52 percent to 7.5 million visitors in September, driven by traffic to the Deal or No Deal site, which increased 998 percent to 1.9 million visitors.
ABC.com and NBC Network captured spots on the list of Top 10 Gaining Properties in September. Also of note was the 33 percent increase to Discovery.com sites to seven million visitors following the untimely death of crocodile hunter Steve Irwin.
MSN TV represented the top TV site overall with 12.7 million visitors, followed by Yahoo TV with 9.8 million visitors and AOL Television with 9.6 million visitors.
Also notable was the 50 per cent increase to TVGuide.com, which registered 4.3 million visitors in September.
Online video sites also continued to gain momentum as visits to the wildly popular YouTube grew nine per cent during the month to reach 20.8 million.
Metacafe gained 134 percent to hit 4.2 million visitors, representing the third biggest gainer for the month. TopTVBytes.com experienced a 72 percent increase to 6.1 million visitors, becoming the sixth top-gaining Web property for the month.
"As the buzz about the Google/YouTube deal turns to the topic of 'who's next?' it will be interesting to watch how online video sites differentiate themselves, and how the major media companies take notice," said Flanagan.