Reaching your target audience means knowing them. Knowing who they are, what they’re interested in, how they navigate websites, and which devices and web browsers they’re using will help you configure your website to be exactly what they’re looking for.
Using Google Analytics, you can gather data for each of these points, and decide which browsers are worth investing time and money in supporting.
As a general rule, we currently support IE9 and newer, as well as the latest three versions of Chrome and Firefox, and the latest major version of Safari.
Edit: As of May 1, 2016, we now generally support IE10 and newer, and only the two latest version of Chrome and Firefox, plus the latest major version of Safari.
Users that navigate our sites with unsupported browsers are shown a message that they should update, if possible. This message is driven by browser-update.org, and is quick to install and configure should you choose to customize the list of supported browsers.
We use a similar methodology for devices, but since most devices now have modern browsers installed, we just need to ensure that the websites work nicely on every resolution.
Quite a bit of our testing happens on physical devices, but we also use BrowserStack to test anything we don’t have available in-house.