I show my displeasure with gaming developers/publishers when I buy used games. My understanding is they don't get a cent from the sale?
Yes, you are correct. But in some jurisdictions, doing so is illegal.
The most permissive is the EU:
"An author of software cannot oppose the resale of his 'used' licenses allowing the use of his programs downloaded from the internet. The exclusive right of distribution of a copy of a computer program covered by such a license is exhausted on its first sale. This was decided by the Court of Justice of the European Union in a case of Used Soft GmbH v. Oracle International Corp.."
http://www.cio.com/article/709990/EU_Court_Rules_Resale_of_Used_Software_Licenses_is_Legal_Even_Online