A long time ago there was a WordPress plugin that let you configure it like so:
You make a page and put whatever you want on it – so lets say I have a weight loss blog and I make a page about XYZ Weight Loss Product. The page would be www.myweightlosssite.com/xyz-weight-loss
If you visit that URL directly, you see the regular content (a review of the product, etc.).
However, the plugin would let you set a random string, so the…