eMarketer is now forecasting that US retail e-commerce sales (excluding travel) will contract by 0.5% in 2009, falling to $133 billion. But - and here is the good news - as the economy improves, online sales will return to the double-digit growth rates seen prior to 2008.

Growth will come from online buyers who shift a greater share of their discretionary spending from stores to the Web. Pent-up consumer demand, especially among affluent online shoppers, will provide an additional sales boost.

By 2012, e-commerce sales growth will begin to decline - resuming another trend seen prior to 2008. This will be due to the inevitable maturation of the e-commerce sales channel, as growth in new online buyers approaches saturation.

All told, from 2008 to 2013 retail e-commerce sales will increase at a 9% compound annual growth rate (CAGR).



eMarketer benchmarks against the US Department of Commerce (DOC) when forecasting e-commerce sales. The DOC estimated online sales rose 4.6% in 2008, reaching $133.6 billion.



But most of this increase came in the first half of the year. After year-over-year growth rates of 13.3% in Q1 and 8.7% in Q2, sales grew only 4.6% in Q3 before plummeting nearly 5% in the important Q4 holiday season.