Board Thread:Game Discussion/@comment-11264457-20130812145120/@comment-11067648-20130813021447

Yes that's it - use them, then level up. But don't level up if you are about to get a free cube in like 10 minutes, etc. Wait till you get the free one, use it, then do the final scan to level up and get 3 more.

Although if you get desperate you might just scan like crazy and forget the free cubes.... depends how low on stocks you get and how nuts the final day is!