A few points to keep in mind:

1) You do not have any contract with pronamer.com. Listing of your domain names on pronamer.com does not require exclusivity, which means that while your names are listed on pronamer.com, they can still be listed on other websites in an effort to get sold through other domain brokers.
2) Unlike many other brokers such as godaddy.com that charge a hefty commission, we only ask for 6% of the sales which is one third of the commission godaddy collects.
3) It is easy to use pronamer’s domain brokerage service. Simply send us the list of your domain names with your desired prices at support @pronamer.com. And place our name server names for your domain names, that is, sn1.this-domain-may-be-for-sale-at-pronamer.com and sn2.this-domain-may-be-for-sale-at-pronamer.com. Placement of these name server names will not affect the functioning of the name server names you are using currently.
4) We will promote sales your domain names including a listing of your domain names on pronamer.com website.

If you have any questions, feel free to contact us.