Google has this thing where when you search for an item, certain ads appear on the right side of the page. These ads are collected from a Google database to try to match to your search, in turn giving you relevant ads.
Of course, there matches aren't actively moderated, so some funny things may slip through. For example, Google the word "Braille" and look at the second sponsored link on the right.
It looks like Google has done something to change this, attached below in a screenshot of the search. Click on it for a larger picture and take a look at that second sponsored link.