In an attempt to boost my commissions via affiliates on my eco-gadget review site EnviroGadget, I wanted to see if I could improve the number of visitors clicking through to the merchant website. I don’t get a commission for all of the products I review on EnviroGadget. However, for the products I do earn a commission, I wanted to make sure that I was getting as many people clicking through my affiliate links as possible.

Therefore I decided to run some experiments with different types of button. Just by changing the colour of a button and changing its text a little, I found a way to triple my click-through rates (CTRs)! Yep, you read that right, triple! Read on to find out how.

The Technology

I have some relatively complex code that I’ve written to handle the affiliate tracking, and it’s beyond the scope of this article to explain it in detail. However, I’ll cover the basics. My affiliate tracking code allows me to create a URL like this:

http://www.envirogadget.com/recommends/a-solar-powered-gadget/g_bn

When that URL is clicked, it redirects the user to the product page on the merchants website, dropping a cookie to ensure that if the user makes a purchase on that website, I get a commission.

The ‘a-solar-powered-gadget‘ part of the URL is the code for a particular product. The ‘recommends‘ part of the URL tells a script on EnviroGadget to redirect a user to a product page using the product code I just mentioned.

The ‘g_bn‘ part of the URL is an example of a special tag that I can use for additional tracking. So I could link to a product using the URL above using many different coloured buttons. If I used a different tag for each different button, it means I can track how many times each button can get clicked. This is what I used to test the different buttons in the experiments below.

Experiment 1 – The Hypothesis

All my affiliate buttons started off being a green Buy Now button. However, I wondered if a contrasting button colour would out-perform my green button (especially as the rest of the site is themed with green). I also wanted to test different button texts too, just too see if the wording had any effect.

Hypothesis 1:

“I expect contrasting blue buttons to outperform the more subtle orange buttons on click through rates”.

Hypothesis 2:

“I expect that the less imperative More Info buttons would outperform the stronger Buy Now buttons”.

Experiment 1 – The Results Data

Button Experiment 1 - Orange and Blue

Notes: I was told that “Shop Now” was a good button text to use, so I wanted to test that. For some reason, I didn’t use green in the first experiment. Can’t remember why!

Experiment 1 – Conclusion

From the results, it’s clear that my initial theories were completely wrong!

So the results show that the orange buttons considerably outperformed the blue buttons. The orange Shop Now button more than doubles the CTR compared to the blue button. Perhaps this has something to do with the emotive effect of colours, e.g. warm v.s. cold colours. Even still, the orange buttons are harder to see with a green background, and blue is more of a contrast to green.

The results show that More Info is a waste of time, performing the worst overall. However, Shop Now is the strongest performing text, with Buy Now being a close second.

Based on these results, I realised I needed to test some more combinations as my assumptions were very wrong.

Experiment 2 – The Hypothesis

Following on from the first experiment, I thought it would be wise to compare the performance of my existing green Buy Now button against orange buttons. I also wanted to test red against orange and green to see if it had any significant impact.

Hypothesis 3:

“I expect that the brighter red buttons will outperform the green and orange buttons, with the red Shop Now button being the best button for the highest CTR “.

Experiment 2 – The Results Data

Button Test 2 - Red, Orange and Green

Experiment 2 – Conclusion

I had clearly learnt something from the first experiment, and my theory was spot on correct in the second experiment. However, the range of values I obtained was very interesting.

The results showed that using a red Shop Now button (21% of clicks), rather than a green Buy Now button (7% of clicks), there’s a 3-fold increase in clicks through to the merchant website!

In general, red outperforms orange and green. The Buy Now and Shop Now are strong call-to-actions, which resulted in a high CTR compared to Buy This. I’ve not been able to come up with a reasonable explanation for the poor performance of the Buy This button text.

Overall Conclusion

From running these experiments, I learnt 3 things. These 3 lessons are:

• Check your assumptions – I was making incorrect assumptions, so testing my assumptions really paid off. I spotted my mistakes.
• Experiment and track everything – When you do test something, collect as much data as possible so you can analyse it.
• No-one will do it for you – I had to run my own experiments to learn my own lessons. Don’t rely on my data either, test your sites yourself too!

I hope you enjoyed the article and that it motivated you to run your own tests. If you like the pretty graphs, please leave a nice comment, as they took me ages to create!

Update – 30th Sept 2009

John Andrews wrote a great complement to this article on Always Be Link Building. John quite rightly emphasises the point that button colours, and therefore their respective click-through rates, are very specific to a website and its design. So just to re-iterate, test different button combinations yourself, don’t rely on my data alone!