Gwynn,
First off what is a gum pole?
Now on to also boughts, if you run a free promotion expect anything and everything to show up in the also-bought. Those tend to be the buyers that stock up on everything.
Now I haven't stocked up in a while but to give you a general idea, here is what I might pick up...
Gwynn's biography, Philip's history, Wayne's sea adventures, Becca's kids books, everyone's Sci fi, some mysteries, cookbooks that look good, craft books, organizing books, prepper books, erotica, romance and whatever else catches my eye. The occasional how to write a kindle book though those are mostly for laughs.
Not to mention the trips from here to grab a kboarder book or 3.
Amazon just picks random books in my you might like section.
Hope this helps.