An advertisement is read as persuasion, a voice telling you what you should want. Dream books link it to desires shaped by others and to questions of what you truly need.
Has this come up in your dreams before? What was going on in your life then?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.