As almost everybody mentioned above, i agree that your domain name should be relevant to your business name. Also keep it short and sweet and easy to type. Try to avoid being similar to existing names if you want your customers to stay with you.
Before there were a lots of impact to choosing a domain name But now its not. If you are choosing a Domain name Just keep in mind about your business niche. Always try to choose short Domain as it More cachy and memorable, less mistyped and less typo found. Always try to register related domain like if you registered .com alos registered .org .net and country specific domain.