From the rules:

TO ENTER: During the Sweepstakes Period, you can obtain a code in one of 3 ways: 1) by purchasing a participating NIVEA product at participating retailers; 2) without making a purchase, by going to www.sweepstakes.niveausa.com/freecode and following the directions provided, and upon successful completion of the directions, a unique code will be emailed to you at the email address you provide; 3) without making a purchase, by attending an event where Anniversary NIVEA Crème Tins will be distributed. For a list of participating NIVEA products, visit www.niveausa.com.

I did # 2 & the code popped up in my email inbox right away, although when you submit your email it says it can take 2 days.