When I checked my "activity," I was appalled by two glaring facts:
How much time I had wasted looking at inane dreck, AND
How many times I had fallen for "click bait"
As a result, in addition to wholesale deletion of my history, I have resolved to be MUCH more discriminating in what I click on and to regularly sweep the history clear.
Google, Facebook, LinkedIn, Twitter - All combined it's pretty interesting what they trade/sell/whatever with each other. Add in the NSA and - Well... I'm too old to care much, actually.