The fallout from the September 11 attacks hit the online sector disproportionately hard, according to Nielsen/NetRatings.

Whereas total retail sales dropped 2.4% from August to September [WAMN: 15-Oct-01], online spending tumbled 15% over the same period from $5.56 billion to $4.7bn, the lowest monthly total since April.

The number of internet shoppers jumped 1.5m from August to 38.6m, but their average monthly expenditure on the web dropped from $150 to $123.

A major contributor to the decline was the effect of the attacks on the online travel sector, where revenues tumbled 22% in response to grounded flights, concerned passengers and restricted routes.

Sean Kaldor, the research firm’s vp–analytical services, explained that travel makes up around one-quarter of online sales, “so a downturn in this critical category dampens the entire e-commerce sector.”

However, it was not all bad news – September’s online sales came in 54% above their level twelve months before. Doing particularly well are internet book retailing, which soared 148% year-on-year to $300 million, and sales of clothing and apparel via the web, up 79% to $494 million in September.

News sources: Financial Times; Wall Street Journal