It's not uncommon to find that the domain name you wanted for your new company is owned by someone else. Much of the time, this is due to that other person already having a similar or even identical name to what you wanted to use, especially if you were looking for a domain that was your real name (e.g., JohnQPublic.com). However, other people have purposefully snapped up and registered domain names for the purpose of getting paid to relinquish them. No matter the reason, if you find out that someone else has a domain name you want, you're best off going through a domain name broker. However, working successfully with a broker takes preparation.
Be Realistic With Your Range
Brokers ask you for a range that you're willing to pay for the domain name, and you need to be realistic with this range. Do not give a laughably small minimum, so research the typical cost of the type of domain name you want. Also, ensure the maximum is something you can definitely afford. You don't want to find that the broker has successfully gotten you a domain name and now you can't afford to pay the price. And remember that your broker gets a commission, so your maximum price should still allow you to pay that extra fee on top of the domain name payment.
Understand That the Other Person Might Not Want to Sell
Domain name brokers are very skilled at getting others to relinquish domain names -- but it doesn't always happen. Sometimes a person or company just does not want to sell, either because they truly want that domain name, the domain name is already heavily associated with that company in its customers' minds, or they just don't want to deal with changing all their stationery no matter what you're willing to pay. If the broker can't get the domain name within a certain amount of time (often 30 days), that's it, and you should be prepared to end that attempt.
Go After Only Those Domain Names You Truly Want -- Because You Might Get Them
So maybe this or that person might not want to sell. But it's also true that they could agree to sell, and you've got the domain name. This means that you have to be sure that this domain name really is the one you want. You don't want to go after one that sounds OK only to regret it the instant the broker tells you the negotiations were a success.
Once you have the domain name, the broker's company can help you attach it to your websites and accounts. If you don't get the domain name but can think of another that might do, the broker can see about negotiating for that alternative name. Brokers are on your side and can walk you through what needs to happen.