Forty-four percent of respondents plan to do more of their holiday shopping online this year than they did last year, the MyBuys survey conducted by Harris Interactive said.

With growing numbers of people shopping online, "it is more important than ever for online retailers to differentiate themselves," in large part by offering as personalized an online shopping experience as possible, the researchers said.

While 80 percent of online U.S. shoppers buy products Web retailers recommend, 62 percent said product recommendations were rarely personalized to their tastes, the survey found.

To improve sales, retailers should personalize online shopping by recommending brands and categories customers have shown interest in, 53 percent of respondents said.

Sixty-five percent said they would also like retailers to offer e-mail alerts when out-of-stock products arrive, the survey found.

Harris conducted the telephone survey of 2,480 U.S. adults Nov. 1-5. Figures for age, sex, race or ethnicity, education, household income and other factors were weighted to bring the sample in line with the actual population.

Harris would not give a margin of sampling error because it said such a characterization was misleading.