A bit of a question, but I wanted to start this thread in this section because it can be seen from different views:
How can you get attention to your domain sales on a listing service such as Afternic or Sedo?
Unfortunately, it's not a question of exposure.
There are millions of domains on sale and no amount of publicity will help if they are bad and nobody wants them.
If you have good domains, end users will find you. They will first check if the domain they want is available, if they want it, they will visit the site if any, or use your contact details from the whois record.
They will bypass the marketplace most of the time, unless the domain is parked there.
But do not expect miracles, Sedo & siblings can't sell ice to the Inuits (the kind of seller that unfortunately most domainers would need :red.