I think that what www.DomainPower.com (RDB)has done with travel is the perfect example of why using a platform that is just a parking solution is not always the best option. My own site OrlandoFlights.com makes a CPM of 6x higher now than it did just "parked". Additionally the bigger picture for me, is that I've actually gotten an offer from an end user who has a travel related business in Orlando. I don't think I would have gotten the offer amount that I did had the site just been a parked domain. While the offering was tempting I'm not ready to part with the domain, Orlando I believe is still the tourism capital of the US and most people have got to fly to get there : )