US online retail spending rose by 10% to $34bn in the first quarter of 2010, compared to $31.03bn in the same period a year ago, representing first double digit growth since second quarter of 2008, according to data released by comScore.

According to comScore, eCommerce spending was primarily driven by upper-income consumers, with spending among the $100,000+ household income segment up 14%. Pureplay (online-only) retailers continued to gain eCommerce spending market share from multichannel retailers.

Larger online retailers continued to generate higher growth rates than smaller retailers, but the smaller retailers are finally beginning to see positive growth once again, the firm said.

Gian Fulgoni, chairman of comScore, said: “The first quarter returned the US retail e-commerce market to healthy double-digit growth rates. While these spending gains provide reason for optimism, we should note that upper-income households are currently shouldering much of the growth.

“Should the economy falter in the second half of the year and upper-income consumers return to a savings mode, we could still see growth decelerate. But for the time being, this momentum is encouraging.”