Hide sponsored links in Gmail

Problem

In Gmail, sponsored links are shown on the right side, which is very annoying since it takes up some space. How to get rid of them?

Solution

Install the WebMail Ad Blocker add-on for Firefox.

“Block ads on the right hand side of the screen when using Yahoo Mail, Hotmail and Gmail thereby expanding your message space.”

Customization:

By default, this add-on highlights the current row in Gmail. You can switch it off in its Preferences. Just untick the box Highlight on mouseover.