A/B testing is a way to compare different versions of strategies, particularly for websites or mobile apps, to figure out which performs better. For instance, two different layouts for a website can be presented to two different user groups using this technique; afterward, metrics such as the conversion rate can be reviewed to determine which version makes more sense. This method can be used in determining new strategies and is also very important in getting to the root of technical issues that plague websites. Among the most popular tools for A/B testing are Google Website Optimizer, Visual Website Optimizer, and Optimizely Vertster, etc.