Malwarebytes 3 is an "AV replacement." It is not an AV. It does not incorporate the same old engine for file-infectors and other malware that you find in a typical AV or Internet security suite, the large and inefficient library of signatures, or the bloatware features which are becoming more prevalent.
You don't need to pay for a traditional AV anymore! At Malwarebytes, we have always approached things differently and, as many people know based on their own positive experience with Malwarebytes finding and remediating malware that gets past AVs, we know a thing or two about zero-day malware and their infection tactics. We have always believed that no one product can do it all, and the free AV that comes with modern operating systems, in conjunction with Malwarebytes is all you will ever need.
In today's modern threat world, bad guys have learned how to evade AV protection, making it more important than ever before to be able to disrupt attacks in as many different stages of the attack chain as possible. Malwarebytes 3, layered with the AV (which is the default mode) or as your stand-alone defense, is the most effective approach against modern threats. And if all else fails, you need the best remediation technology available.