If you are a Google AdWords advertiser, pay close attention to a new ad extension recently released, “Social Extensions”.

These will show how many people have “+1” your Google+ page along side the ad. This is basically a very strong social signal. For instance, if I run a search for pizza joints in Reston, Virginia and see an ad that has been +1’d by a couple of people in my Google+ circles, it’s going to catch my attention more than an ad that doesn’t. And I’m probably going to click the ad.

Here’s a short article by Google on this new feature.

For a more in-depth look at the impact of this new feature, check out this article by SEOMoz.

When you pilot these extensions, however, you need to remember why Google does what it does: profit. Google wants people to click ads, as that is how it makes money. And it knows that social signals lead to higher CTR. So, as an advertiser, you need to understand if that higher CTR is translating into a higher conversion rate for whatever your goal might be. If not, you’re essentially getting more clicks that aren’t doing anything on your site.

So, pilot carefully and wisely to see if Ad Extensions are the right fit for your business.