The very controversial Google AdWords Automatic Matching feature has been confirmed to be expanding to other advertisers as early as tomorrow.

In short, automatic matching is a new algorithm used to automatically target new keywords, not included in an advertiser’s set keyword list, in order to use up all of the advertisers allocated budget. So if you are advertising for [Adidas shoes] and you have $10 left in your ad budget for the day, Google might decide to show your ads for search terms as far off as [slippers]. Like, I said above, there is a lot of controversy around it.

Google admitted that they will be expanding the very limited beta, as early as tomorrow. In both a WebmasterWorld and Search Engine Watch Forums thread, an official AdWords representative posted giving more insight into the expanded launch.

The Google representative clarifies that the expansion of this program will be “truly tiny.” Explaining that “automatic matching” will not be going live for all advertisers, but will be expanded to a select number of advertisers, as a continued test of the program. Here is a quote from the statement:

The Google representative said they will be back today to post more details and address more concerns.

Forum discussion at WebmasterWorld and Search Engine Watch Forums.

Update: We have more information from Google on this news. An AdWords representation said that those in the very limited beta will be notified on May 20th but the ads wont go live until June 3rd. They have all that time to opt out of automatic matching.

For more details on Automatic Matching, see here.