Yes, I usually offer mine via DM as in the past, people have spent ages trying different single use codes and wasted their time as they have already been used.
When the threads get busier, there are hundreds of contributors and even more lurkers, therfore codes are used within seconds.
I prefer to give a code to a regular contributor as a mutual appreciation for their input, than leave them to be taken by people who lurk and never give anything back.
That sounds a bit odd now I've read it back, but to me it's the ethos of the Christmas bargain threads community.