You are right, manners are very important. There is a proverb in French telling ''Le client c'est le roi''. That means the client is the king, if we buy something from the store they have to treat us well.

About saying please and thank you is good as well. Mostly people in our modern life don't care about that, but we still have people who care about that and we have to support that somehow. Thanks for the video and please record more videos like that. ☺