Search engine optimization (SEO) is ranked by almost 90 percent of US retailers as one of the most important technologies to help promote their online business, according to a new survey.

A survey published by search service firm SLI Systems indicated email marketing and site search are also considered to be significant parts of an effective e-commerce strategy.

The study, conducted by the firm in conjunction with online survey provider Zoomerang found 87 percent of respondents are currently making use of such methods.

Meanwhile, many expect to make use of social media tools (47 percent) and online video (32 percent) as part of their marketing strategies over the next year.

Susan Aldrich, senior vice-president at the Patricia Seybold group, commented: "Retailers are competing for consumer dollars and they can compete better by bringing new tools to the customer experience."

Meanwhile, a study by ABI Research recently noted the growing popularity of social networking sites among mobile internet users, stating nearly half (46 percent) of those who use the online resources have accessed them via their cell phones.