I made a mistake this morning.

Here’s the data from a TrafficJunky campaign I set up last night:

The campaign used CPM bidding.

If you had to pick three ads, which would you keep?

I picked ad1, ad3 and ad4.

One of them was a bad choice.

Here’s why.

Affiliates are trained to look for the best conversion rate.

That’s pretty smart if you’re bidding CPC (paying by the click).

But when bidding CPM, the best conversion rate doesn’t always mean the best ROI.

That’s because it doesn’t take in to account the clickthrough rate of your ads. Less clicks means your conversion rate is taken from a smaller sample, and it therefore has to work a lot harder.

Instead you should be picking the ads that generated the most revenue: ad1, ad3 and ad6.

In this case, ad4 had the second best conversion rate at 3.56% but it had 3 less conversions than ad6 at 3.19%.

While ad4 was more potent for the users who chose to click it, ad6 delivered more revenue through attracting more clicks and maintaining a respectable if lesser conversion rate.

This is something to keep in mind with any CPM campaign.

We are constantly battling for the best combination of a banner that draws conversions, but also enough clicks.

So here’s the next step.

I’ll take the headline and ad copy from ad4 and combine it with the imagery and CTA of ad6.

It’s a process I documented here that has a useful knack of producing banners that increase profit and obliterate the competition.