U.S. online retail sales recorded their smallest growth in October since comScore began tracking this market in 2001, a signal that this holiday season is shaping up to be a very tough one for e-tailers across the board.

Online retail spending rose only 1 percent last month, compared with October 2007, as consumers worry about the economic woes affecting them and the country in general, comScore reported on Tuesday.

The lower a household's income, the less likely it was to increase spending this October compared with last year, according to comScore's research. For example, households with less than US$50,000 in annual income generally spent less this October than last year. While overall online retail spending from August through October grew 4 percent, spending among households making less than $50,000 dropped by three percent compared to a year ago.

E-tail spending growth has fallen from a high of 28 percent in August 2007.