Are there referral links to any parking services? For example, sedo.com. Is there a referral link I could get to refer other people to join and park their domains there?
Yes there are. Sedo says it partnership, Namecheap / Parked affiliates .... It's easier with Namecheap so far for me
What I do is Check the parking service (example Sedo.com) and check the bottom of the page for things like "affliate" , "partnership" "services" etc. usually this is where you will find the referral programs...another thing I do is "Ctrl F" put the word (phrase) I want and click on "find next" (this function works on my browser..not sure of others) and yes Sedo does have a partnership program http://www.sedo.com/partner/index.php3?tracked=&partnerid=&language=us (lol) you have to click on the services tab and no the sedo link isn't my referral link