How is it NOT structured course? It was literally designed as a structured course teaching you the language step by step. It was made by teachers for students with the intention to teach the language. I am inclined to believe you that it is effective. If I ever get serious about Spanish, I might try it out.

And also, undestading shows like bingo or kids shows requires already existing knowledge of words. You will not figure out meaning of words purely based on watching them.