"Ads by Words Display" is an adware extension that displays pop-up ads within the context of the web page you are viewing. When a user is visiting a number of general pages the program will displays mostly banner ads and some inline-context ads that are completely un-targeted and in many cases promote malvertising from suspicious ad vendors. While Words Display is advertised as a program that displays lyrics on YouTube alongside the music video, the adware is not really concerned with providing better pricing but simply displaying a ton of unrelated ads.
The software can be downloaded from wordsdisplay.com, but is more typically bundled by 3rd party download managers and installers. The Terms of Service simply state on the website: "The Software enables you to find lyrics to any song on YouTube and display them alongside the music video. Our Software will enhance your interaction with YouTube by adding features, functionality and content through your browser. The Software is FREE of charge and sponsored by advertisements and commercial offers that may be displayed to you by Vendors.
The Software and Services are sponsored by third party advertisements and commercial offers and may also contain links to third parties websites, advertisements, products, offers, applications and more (“Third Party Content”). By downloading and using the Software you give your consent to display to you such Third Party Content (by using display ads, pops, coupons, price comparison, in-line text and content recommendations) through Our or Our business partners’ technology."