The problem with that approach is that you find things that tickle your fancy. You find them creative, original and funny... but alas, they don't address a MARKET. You don't consider the perception of the BUYER.
Sure, someone is going to come along once in a blue moon, like winning a lottery and buy a weird domain, but of the millions of domains out there, what's the odd it's going to be you during the year(s) you keep registering it?
And sure, you can take an obscure name, and develop it, promote it, direct traffic to it, and get it to climb up on a search engine with time, effort and money, and get people eventually to notice it, and maybe want to buy it, but... after all of that, why not just consider marketable names that target something of real and recognized value?