Now that the buttons have been around for a while, I have to say that I?d be pretty surprised if Google decided to try out any more.

I?m not aware of anyone making any serious money out of them. The ad units are great. The link units can do pretty well. The image ads not so much. And the referral buttons might buy someone a small coffee once a month... provided they have an audience which has never heard of Firefox.

The real problem with the referral buttons we were offered was that they just weren?t very competitive. There?s a whole range of different affiliate programs that we can sign up to online and the payment terms that Google was offering just didn?t beat what was out there -- a dollar for a download? One hundred dollars when someone you?ve signed up for AdSense breaks a century? You?ll probably do better sending people to some dating site or pushing books at Amazon.

The buttons don?t do any harm. But I don?t think anyone really expects them to do a great deal of good either.

The fact that we haven?t seen any additions to these programs suggests that Google has picked up the message that affiliate programs just aren?t their strong points. In fact, I don?t think AdSense has produced anything yet that beats the basic ad unit. That was a killer idea... and no one?s beaten it yet. We?ve had a few false starts when companies have brought out some attractive new products but the bottom line is that it?s still the good old AdSense ad unit that?s keeping those fat checks coming in.

That doesn?t mean that Google shouldn?t be looking for new ways to make us all a little richer. But they need to be original if they?re going to make it work, and do something that no one else has done.

Or they can just focus on rolling out new formats and adjusting the Smart Pricing so that my prices go up. I?d be happier if they just did that than offer more affiliate buttons.