I thank you for answering... I did not know about this "time of waiting"
I suggest you to put in big letters, to keep your clients informed...
(expecting that you comprehend my bad english)
I will wait for the cd key
The 2-3 bussiness days is the time it usually takes to reply support requests (in this case the CD-key request, you did send it thru the above link? Posts in forum do not count although GOG staff do reply to them on occasion.). If reply takes longer, it's usually best to resend the request as there have been occasional problems with mail server and support may get swamped with support requests at times so yours may get burried. Note that GOG offices are based in Polland so their timezone is GMT +1 (yours seem to be GMT -3 or -4 depening where in brazil you live) and GOG staff works between 8:00 and 16:00 so depending when you send your request, it's entirely possible they'll see it next morning at the earliest.
And just to make sure I'm not misunderstood:
You can send the CD-key request as soon as you purchase a game that uses one (note that single player works out of box as GOG installer comes with generic CD-key).
You need to request it using the support form, forum posts do not count.
The 2-3 days I mentioned is the time it usually takes for GOG staff to reply but it may well come soon after you send the request depending the time of the day and how busy the staff is.
You should check your e-mail account spam/junk folder as some spam filters may mistakenly consider GOG e-mails as spam.