Why does my Dashboard say "Gathering data, please check back soon"?

Question: I have just installed the app but it's not working. The Dashboard is stuck at "Gathering data." What's going on? 

Answer: After installing the app, it can take up to two days to scan your site and generate SEO data. So if you see something like the screen below, check back later. If you see no change after two days, please contact us via the link below and we'll look into it.