Remember Mobile Users!
I do a good bit of web surfing via my tablet, and it’s always frustrating when a site just. doesn’t. work.
Recently, I tried to log in to a technical recruiting site (who should really know better) and was unable to do so. In fact, pressing the “Log In” button rendered the entire site useless. Refreshing didn’t help either. On the laptop, I see that clicking the link causes the login form to appear in a modal.
My guess is a Z-Index issue involving media queries in the stylesheet, but in any case the broken functionality illustrates the need for at least a cursory check on mobile devices.