My wife drinks maybe a pint a month.
I have some non-homebrewing friends that are beer lovers and enjoy my homebrew, except for certain styles. IPAs are no problem finding willing consumers. Stouts & porters, not so much. Sours are hit-and-miss.
I also belong to a homebrew club, and as such we occasionally do events where we serve beer on tap. Stuff like parties, conferences, and festivals. I usually bring at least one keg and sometimes as many as three to these events. That certainly helps to finish off kegs.
Other than that it's pretty much just me drinking whatever I've got on tap until I'm kind of sick of it, at which point I will swap out with another keg. Sometimes I will eventually put the original keg back on tap and finish it, and sometimes I'll end up dumping it several months later. And some beers I make are really huge, like 12-14% ABV, so I will put it on tap for a while and drink a few pints, and then take it off so I can have a breather.