Only for sets I am building. I have a lot that no one ever seems to come knocking for. I doubt any are worth anything, as I never actively chased any, but it'd be great if they could end up on someone's collection that actually enjoys them.

This is a great topic and helps us promo collectors know a bit more about each others beginnings and passion (or lack there of) , for collecting promos.
I started collecting sets back in the early 90's and would often want a promo to complete the set. Then I happened to be in the right place at the right time and asked at a local card store, do you have any promos?
The bloke said one moment, went to the back storeroom and came back with a box FULL of promos, sell sheets etc, and I was hooked. Promo cards became my passion and yes, as many other collectors here have mentioned, I enjoy the hunt, searching and asking around for those elusive promo cards that you know are out there, but just can't seem to find.
Promo card collecting teaches stuff about yourself...Patience, Diligence, Investigation and cataloging skills, and the chance to connect with like-minded folks from all over the world, who happily will share info, trade cards, and generally help with you trying to fill the gaps in your ever expanding collection.
I collect all promo cards, prototypes, mail-ins, convention exclusives, anything promo related, but really, just trying to complete the main checklist...Todd Jordan's 2008 PCE, that book has traveled all over the world with me, that's my main goal, and it's just FUN
Happy to be a Promo Card Collector

I collect for the sets I'm buying and also RA, inkworks & Breygent promo's. I did try and collect Cryptozoic as well but some of theirs have been too rare and pricey. I also have a ton of other promo's from shows & NSU that I "collect".

I used to collect only to complete my master sets.
I collect Outlander cards and those are expensive. Most likely the one I prefer with reasonable prices.