Anyone that has spent time with traditional texts, cassette tapes, etc. and memorizing phrases like "the book is on the table next to the window" sees the value in what popup Chinese offers. While I don't mean to bash the traditional methods as I did learn a lot, and developed a solid foundation, there comes a point where it is very hard to make improvements (at least this was my situation). Your methods are not only fun and effective, but have lighted a new passion for the language that was a bit stale before.