2010 delivered everything most online retailers could have expected, and then some in many cases. According to the MasterCard SpendingPulse eCommerce Index, online sales rose over 15% year-over-year, and ecommerce accounted for $36.4bn in holiday sales.

Search marketing agency PM Digital says retailers can thank paid search for a good portion of that rise.

In the 2010 holiday season, online retailers in the PM Digital Rewind Index boosted their spending on paid search ads 81% from 2009 levels. The year-over-year results: 42% more clicks, a 7% jump in conversions and a revenue increase of 47%.

Those type of results would probably be welcomed in any year, but following the tepid shopping seen during and following the Recession, it’s safe to assume that online retailers are happy with what they received in 2010.

They will also have some new trends to think about for 2011. According to the Index, it was Green Monday (December 6), not Cyber Monday (November 29), that generated the most clicks, orders and revenue.

The stats also show an uplift in activity on Christmas and the day after. As reported by MediaPost’s Laurie Sullivan, “both days saw clicks more than double the monthly average.

The possible implication going forward: it’s not all about Cyber Monday. Retailers will need look at the holiday shopping season as a marathon, not a sprint, if they’re not already doing so.

Not surprisingly, there was a downside to 2010’s online retail boom: all of the competition drove
CPCs up by 22%, and average order value only jumped by 2%. That means that online retailers will need to focus on strategy in 2011.

For instance, PM Digital says that its geotargeting strategy was a boon for the retailers it services in 2010. Expect similar strategies to be experimented with and employed in future years.

Photo credit: Bart Fields via Flickr.