Just seems a bit odd to bid on keywords that loosely, as well as the inconsistent ad variations across different regional versions of Google.
For instance
"Used Tampons" doesn't trigger ads on google.ie, but 'tampons' does
tampons - Google Search
Google.com.au triggers ads for 'used tampons' but not 'tampons' -
used tampons - Google Search
Kinda interesting the different strategies used in different locations.
Doesn't explain why they're specifically bidding on 'used tampons' which lands on a 'tampons' search on ebay
(bearing in mind, the nature of the search and it's usefulness)