If you intend to trade as a business on eBay as opposed to an individual you need to choose your ID with care. A little forward thinking goes a long way; would you buy a health care product from wayneluvstracy27? What about from total-healthcare? It’s a no brainier really. Total-healthcare gives a professional image immediately and it describes and defines the business focus from the start, wayneluvstracy27 does none of these things.
If you have chosen a bad ID or you now want to trade under your personal ID, you can still change it. However if you have a lowish feedback score if might be worth starting a new eBay account and starting from scratch. Buyers will check out your recent feedback. They may not be as willing to part with there hard earned for that exotic skin cream you are now selling when the last item you sold was your Barry Manilow greatest hits CD. It’s all about perception, of you and your services. You may well be operating from your kitchen table but that does not mean that your service is not as professional as other sellers.
When I am choosing an ID I try to avoid the use of the underscore _ simple reason, if you wish at a later date to register a domain name the same as your eBay ID (recommended) look at the following examples: www.pet_parlor.co.uk (there really is an underscore in this domain name) or www.pet-parlor.co.uk see the difference?
Why would you want to register your eBay as a domain name? If you are even moderately successful someone will get there before you. It’s all about thinking ahead. Should you wish to setup a website to backend sales then you already have the domain name and your eBay ID as reinforces for each other.