You could just answer this by saying that you used a different platform to cover the shortcomings of the other. This isn't a bad answer. In fact, it can be part of a good answer. However, you should definitely know how to overcome or at least deal with limitations on social media platforms. For example, Facebook has severe limitations when it comes to organic (non-paid) reach. One way to overcome this without paying on Facebook is to use email marketing and subscription-based methods to gently guide people to the page with links and suggestions If you have your own awesome anecdote already, that's even better!