You might be able to find information because you know where to look! Often times the text is too tiny for visitors to read, leaving the visitor to resort to finger gestures (pinch and zoom) in order to find information. Mobile optimized websites are built for smaller screens and are easy to read and navigate on smartphones.
Some newly developed websites implement a responsive design in an attempt to leverage their existing website. I some cases this works well, in other cases it’s just too much information to squeeze on a small screen. A mini version of your conventional website could still be turning away customers and prospects without you even knowing it!