I didn't say that this product will "block" sites (traditionally speaking). For example, if you need StackOverflow it can replace it's UI with only a search bo

I didn't say that this product will "block" sites (traditionally speaking). For example, if you need StackOverflow it can replace it's UI with only a search box and results list, preventing you from clicking related links. When you go on reddit, it could asks you which subreddit you need and why before letting you in, reinforcing the reason you need to visit the site. I think it can be powerful - requiring active input from the user as to what his intentions are. If you need to write "I'm really bored" as a reason you go on Facebook, I think there's a pretty good chance you'll end up closing it. I believe there are hidden patterns that you might be able to break when the product helps you see and understand these patterns.