By giving people random user names, you force them to do more work long term.
Step 1: Click the one button and get my user name
Step 2: Go write it down somewhere
Step 3: Cookie expires/is cleaned - now user forgets the random user name or email.
Step 4: Go look it up, enter info
Agreed - with things like usernames and passwords, you want to make it feel like they're being involved in process, which helps create a connection. It also helps with the 'stickiness' of your website.
If I were to give 2 real world examples, imagine a conversation between 2 people.
In conversation one, Person A is constantly talking at Person B, not too, but at - Person B doesn't feel included in the conversation, so probably loses interest and tunes out at some point.
Conversation two is a simple exchange between 2 people, with information going backwards and forwards. This conversation is more 'sticky'
If anything, I would work at ensuring that you have minimal information required at signup - username, password, email address, simple and interactive.
To take it one step further, one could argue that this is infact the perfect configuration for signup information because you are requesting 3 pieces of simple information which is perfect given the human brain's natural affinity to the number 3.
Example 1) Comedians usually deliver jokes with the punchline as the third part of the joke, because it has been proven to be naturally funnier...
Example 2) Lots of marketers like to highlight that their product takes only "3 easy steps".
Thats not to say that thinking outside the box is a bad idea - kudos for giving it a try dude :)
I want to feel involved. Plus, if I'm using a website to the extent that I'm going to want a username and password I pretty much expect that I may have to fill out more information upon registration so it is not as bothersome.
It also depends on what your website offers. If you are selling products (like ebay), instant gratification also comes into the picture. Whenever I'm shopping online and go to "checkout" I'm much more satisfied when I my information is already in the system and I can checkout with a few clicks, rather than having to enter all the information, etc. before I can actually purchase my product.
Re: your reference to Craiglist, sometimes I wish I did have an account with Craigslist so I could see my selling/buying history or have my email address or phone number stored.
Again though, depends on what your website is offering...
Step 1: Click the one button and get my user name Step 2: Go write it down somewhere Step 3: Cookie expires/is cleaned - now user forgets the random user name or email. Step 4: Go look it up, enter info
Repeat steps 3 & 4 ad nauseum.