A/B testing is an efficient way of finding out what’s working and what isn’t. It’s becoming increasingly mainstream because it is fundamentally simple and with such a wide array of tools available its pretty much free to do.
Search Engine Watch has published a useful and comprehensive article outlining 23 tips for A/B testing.
The article explains the importance of testing every significant variable, and to pay particular emphasis on the main factors that are likely to affect conversions – such as headlines or design formats. The article also warns against being too obsessed with A/B testing – for example, if your test tells you one thing, but many clients are telling you the opposite, you should probably put more weighting to what your customers are saying.