Conversion rate optimisation is a fascinating science.

For example, if you want to double the number of email sign ups you get then you could do one of two things:

- Double the number of visitors to your website
- Double the conversion rate of your email sign up form

But doubling can seem a bit daunting – is a 100% increase realistic? It may be more realistic than you initially think. If you make improvements in both of these areas above, then you don’t need to increase them by 100% double your conversions, you only need a 50% improvement in each area as these will add up to an overall doubling of conversions.

Here’s how the maths works:

- If you have 10,000 visitors per week and a conversion rate of 1%, then you get 100 sign ups per week.
- If we achieve a 50% increase in the number of website visitors – so that’s now 15,000 – but keep the conversion rate the same, then we get 1% of 15,000 which is 150, or an increase of 50.
- If we also increase the conversion rate by 50% then we get 1.5% of 10,000 which is 150, or another 50.
- If we do both of these things then we end up with 200 per week, which is the desired doubling.
- So we can achieve a 100% increase in conversions through an increase of only 50% in two areas.

You can even break it down more than this so that you can aim for smaller improvements in performance from an ever wider number of factors, all of which will add up to an overall doubling.

But if all these numbers get a bit confusing, then you can think of it another way. Instead of trying to improve the whole thing in one go, you break it up into smaller components and try to get a smaller improvement in each individual component. These small improvements all add up to an overall larger improvement. It’s more than a philosophical change, it really helps. Because when you break it up you begin to realise that some of the small improvements aren’t expensive, and sometimes they’re even free.

This is really only a brief introduction to this topic. For a much more in-depth look at it I can do no better than to recommend the conversion rate experts.