Everyone’s gone a bit mobile web mad over the last couple of years, anyone who’s anyone has an app and “m-Commerce” is a buzzword we’re hearing alot at the moment.

While few would argue that having an e commerce site that works well on a mobile is a good idea, working out whether optimising your store for mobiles will generate enough extra revenue to cover the cost is well worth doing before you take the leap.

Fortunately, this is a relatively easy calculation to do provided you have goal or ecommerce tracking set up in Google Analytics.

First, establish what your overall conversion rate is, for the sake of this post we’ll say that it’s 5% across your whole site.

Now, using the advanced segments, find out what your conversion rate from mobile devices is. We’ll say in this case that the site isn’t optimised for mobiles and that the conversion rate is 1%.

Next, find out how many visits you get from mobile devices from the mobile tab under Audience in Analytics, we’ll say that our example site gets 1,000 mobile visitors a month. At 1% conversion rate, this means you’re currently getting 10 sales a month from mobile, if a mobile theme raised this to 5% – the same as the rest of the traffic- that would be 50 sales.

So would the extra revenue from 40 extra sales a month justify the cost of optimising your site for mobiles? This should be a fairly easy question to answer, and it’s one you can answer with figures, not guesswork or buzzwords.