One of the few arenas that Google hasn’t dominated over the last few years has been product search. You’d almost be forgiven for not realizing it had a comparison shopping service.

Well November 2008 was the month where all that changed. Having lurked in the shadows of comparison shopping leaders Yahoo! Shopping and Shopzilla for years - Google Product Search finally forged forward.

According to market tracker ComScore, Google Product Search soared a whopping 786% in November 2008, compared to Nov 2007. That represents about 11.8 million unique visitors, and the biggest one year increase ever by a shopping engine.

Google Product Search, which was formerly known as Froogle, has had a serious change of fortune. Back in 2007, the service actually experienced a decline in traffic - which inspired the renewed focus on the service. A change in name was just the tip of the iceberg.

“We have made a number of changes to improve both the relevance and the quality of products that are displayed, to reduce erroneous entries and display popular products (making the site) easier for consumers to understand and more useful,” said Jerry Dishler, Project Manager for Google Product Search.

In my opinion, the two primary reasons for the drastic improvement are integration and economic conditions.

Firstly, Google has done a great job of integrating all their search offerings into the core web search (i.e. Universal search). By effectively listing product search results directly into core web listings, it was inevitable that once they got the formula right - traffic would soar.

Secondly, the current financial situation has more and more shoppers seeking bargains - which promotes more comparison shopping. Given Google’s dominance of search in general, it would have been the default place to start of shoppers looking to compare prices.

While this all bodes well for Google, what does it mean for retailers looking for new marketing opportunities?

First and foremost, being included in the comparison shopping results is pivotal. This is achieved by regularly submitting a data feed of your products to Google.

The other way to leverage the increased traffic to Google product search is by advertising on relevant searches via AdWords. It’s the perfect opportunity to get your products and brand in front of motivated buyers.

I’m surprised it’s taken this long for Google to gain ground in the comparison shopping stakes, and I wouldn’t be surprised to see Google take the lead in 2009.