I've had good and bad experiences:<p>Good example: Domain is already owned, but the owner is in the business of buying and selling domains (you can usually tell these domains because when you visit them, they redirect to sales/contact-us page). I make an offer, he counter-offers, we're good.<p>Another good example: Domain is already owned and listed on a marketplace like Sedo.com. I purchase for the buy-it-now price, sedo takes care of the escrow and name-transfer, we're good.<p>Bad example: Domain is owned by some random person who bought it years ago and isn't really sure what it's worth. I check the Whois listing and email the contact address there. I might hear nothing back at all. If I do, I make an offer, their counter-offer might be an order-of-magnitude higher, or they're not interested in selling at all. Nothing you can really do in that situation.<p>Another bad example: The domain has not been renewed by its original owner, several folks have tried to backorder it, so the registrar puts it up for auction. This is worst case scenario. There is no option for tactful negotiation, just unbridled bidding against everyone else who wants the domain. I've never come close to winning such an auction, and I've tried several times.