Why? Why is there only "Windows", and "Mac", for most people? Is it a lack of advertising? Lack of support? Lack of, simply, knowledge that Linux exists? Linux has so much to offer: added security, more stability, repositories, an eager, helpful community, customization, freedom! Why stay with bloated, proprietary, and costly operating systems when a free, better alternative exists? What do you think? What's the invisible barrier(s) preventing Linux adoption? Should it be sold in stores? Should there be a massive advertising campaign? Share your thoughts and feelings on this. I have tried many times to convert people, and I always meet indifference, or even anger. Any help?
Note: please do not turn this into a debate. This is a real question, and I like, like potentially many people, wish to know the best way to spread the word.
EDIT: I'm asking this here because I believe Ubuntu has the best chance to convince people to switch from other OSes.