Did you know that you can open a link in a new tab by middle-clicking on the link with your mouse? Or, open all bookmarks in a folder at once by middle-clicking on the folder in your bookmarks bar ? That wheel in the middle of your mouse is good for more than just scrolling—in fact, the button can do quite a bit. Your middle-click mouse button—also known as your scroll wheel—can be an effective tab management tool in both Chrome and Firefox. Your browser—whether it’s Firefox, Chrome, or even Internet Explorer—makes better use of the middle mouse button than anything else.
If you’re on a laptop and don’t have a middle mouse button, you can probably still perform many of these actions. Many laptops will simulate a middle click if you press the left and right buttons simultaneously, or you can add that ability with a program like AutoHotkey. Of course, most of these things are easily accessible from other places, too—they’re just a bit quicker if you have a middle mouse button.
You’ll also notice a lack of Mac shortcuts below—likely because Mac mice don’t usually have a middle mouse button. You can add in a gesture with an app like MiddleClick for the browser shortcuts, if you so choose.
http://lifehacker.com/the-many-things-you-can-do-with-a-middle-click-on-your-1565756062