I love this passage from Karen McGrane talking mobile websites:
It’s frustrating and confusing for them if you only give them a little bit of what you offer on your “real” website. If you try to guess which subset of your content the mobile user needs, you’re going to guess wrong. Deliver the same content as your desktop user sees. (If you think some of your content doesn’t deserve to be on mobile, guess what — it doesn’t deserve to be on the desktop either. Get rid of it.)
Unfortunately McGrane has it wrong, the section that should be in parentheses is the entire article, with the bit that is in parentheses in bold instead.