Are you using a particular parking company right now? I haved used Sedo in the past and now use NameDrive. If you have specific questions about either Sedo or ND, feel free to PM me.
I have them parked at sedo - two of them get okay hits (20-30 per month), the others get very few (8-10). I get almost no click revenue - usually like 50 cents per month. Any tips or suggestions? Maybe the names are just awful....
been studying various programs for quite a while now.
NameDrive is the best overall BUt there are other good ones. It really depends on your situation. If your plans calls for selling or holding on. and where your traffic is coming from. Not all accept (pay for) global traffic.
some get better traffic. some get better click through. Make sure you spemd some optimizing the page both for traffic and for the featured ads. Some have a long approval time others are instant.