I've used my CP more than you this year, argolfer, though not as heavily as I wish. So far this year I've brought my companion on 7 one-way trips. By EOY we'll probably reach 10 though nothing's firmly planned at the moment.
Nominally we've saved $1800-2000 so far this year with companion flights. I say nominally because with CP some of the trips we choose to take we otherwise would not take at all. Or we'd choose to drive rather than fly (e.g., a recent NorCal-SoCal trip). Or we'd book on a different airline that's cheaper than Southwest without CP. This also means that the cost to WN is not as simple as $1800-2000. They're getting extra revenue from me on flights I'd otherwise buy from a competitor or not buy at all.