Online marketers looking to track what actions their audiences take on their websites may wish to take up a new advertising system launched by Google.

Under the pay-per-action (PPA) facility, companies will pay whenever a user carries out a defined action on their website, such as making a product purchase or signing up to a newsletter.

Google claimed that by using PPA, companies will "only pay for precisely the actions [they] want users to take", giving firms more control over their advertising spend.

The search engine giant added that the facility is designed to compliment existing cost-per-click and cost-per-impression advertising services.

Currently the facility is being trialed on US-based websites within the Google content network. It is set to be rolled out to AdWords advertisers within the next few weeks.

Writing on the Hard Life Freelancer's blog, Perry Marshall claimed that although advertising on Google using AdWords can provide an initial steady stream of online revenue, marketers should be aware of the many other online techniques available such as affiliate marketing and search engine optimisation.