PPC or PPA?

Pay per click has been with us for a while and it has proved to be highly popular with web marketers. It offers immediacy, targeting and test data. What it hasn't done up to now is offer every advertiser low cost. Some advertisers find that Pay per click advertising is highly expensive since they find themselves paying for clicks which don't convert into sales or relationships which can be exploited subsequently.

Google is experimenting with Pay per action advertisements. During the experiment, these will be available only on Google's content network, but because they focus on advertiser-defined actions they may ultimately prove to be even more popular than Pay per click ads.

While the experiment is in beta, there are some additional limitations for advertisers wishing to take part:

• U.S advertisers only
• You must have conversion tracking (or be able to implement conversion tracking code) on your website

Advertisers will have to think through just what an action (a sign up for a newsletter, a sale of a book or another product, for example) might be worth to them and that will no doubt mean that bid prices for sales actions could rise sharply which will do Google's share price no harm at all.

I can't wait to see this experiment roll out beyond the content network and then into Europe. This looks as though it will be a very exciting innovation.