Google is once again at it, with a new feature that has been standard for a while now on the other major comparison shopping engines.

They’ve just announced on their blog that they’ve unveiled a new taxonomy system for merchants to categorize their products under.

It will be interesting to see how this affects how a merchant performs with this new system, as Google Shopping differs mainly from all the other engines in that it lacks the ability to browse for items. For instance if you go to either NexTag or Pricegrabber you automatically have categories to browse through from the home page–while Google Shopping lacks this feature, and the Google Base homepage is severely limited.

What it can help though is after a search is performed, potential customers will have the option, as on the other engines, to simply browse through the categories that relates to the search.

However, this is possible at the moment only because the other engines more or less enforce products into categorization–while products that remain uncategorized (or categorized incorrectly) suffer from a lack of exposure.

Since Google Base/Shopping is still a free to use engine, it will be interesting to see how heavily this will be enforced upon its users–since merchants are more likely to ignore what’s going on with their Google campaigns, and since categorization can be highly tedious work. Not to mention that Google mentions that using their taxonomy is simply “recommended”, and that merchants are “free” to use their own taxonomy systems.

For now it seems like the taxonomy system will mainly help in terms of search relevancy–meaning a merchant may rank higher if a search phrase matches what is in his “product types” header.

Either way it certainly is a step in right direction for Google, and gives merchants one more way to separate themselves from the others and increase their relevancy.

You can download the complete system, with 2,570 sub categories in total, here.

So NexTag didn’t quite follow on Shopping.com’s lead of reducing CPC rates, but instead have done the typical raising of rates, along with adding the following new categories for Q4:

• Electronics / GPS Devices
• Electronics / Accessories
• Gifts / Gift Cards

GPS’s have been the hot products over the past year since prices have dropped considerably on them–it wasn’t too long ago that standalone systems were in the thousands of dollars range–and other than the what’s been going on in the economy lately, there’s little reason to think they won’t continue to be a hot gift choice.