I got a promotional code but I can't use it because an error said; "Oops, this promotional code was already entered in another account. Promotional codes can be used just once". For your information i never use this code yet. may get another promotional code?
Re: promotional code
Your account may be too old. Promotional codes are often intended to help new advertisers get started with AdWords, so they might not work if your account is more than 14 days old.
Google works with certain third-party partners who offer these promotions. If you receive a promotional code from a website or service with which you have no business relationship, please be aware that the code may be invalid. If you're about to sign up with a service offering you an AdWords promotional credit, make sure you confirm that the service has a relationship with Google. promotional code didn't work, you might have mistyped it. It's worth trying again, paying attention to any capital or lowercase letters in the code.
Hope it helps you.