In my experience over many years I have always avoided "Yahoo" on results pages.
I have found their search results to be irrelevant to my search, loaded with a lot of marketing "buy me" links
When I search the web now with DDG how much is Yahoo search-engine input ?
case in point:
1. how to find DVD burner model on Toshiba
- plenty of results to sell me Toshiba, sell me DVD/CD drives, online converters
2. how to copy USB data to DVD ?
- loads of DVD to USB -- mostly apps "DVD to USB -- no "how to"
- after 45 minutes of scrolling down the results list ... I gave up
Whenever I want to buy something I use Startpage/Ixquick
Its very difficult to escape the clutches of Google, YouTube and they "gotcha"
I am very concerned about "Yahoo" as I find their results very weak, and mostly irrelevant