parking is for domain monetization of domains with existing Search Engine Optimization traffic already not the other way around, parking is not to gain traffic but building, developing, advertising a forum, directory or blog domains is to increase it's traffic later you can monetized it either putting adsense on it, or receiving payment for advertisements.
one good example is namedrive.com a domain monetization and domain parking services, it's not even listed on google, either google banned it or namedrive.com requested delisted from google's directory;
http://www.google.com.ph/search?hl=t...=Hanapin&meta=