This presentation covers my experiences combatting phishing and fraud using DMARC and assorted other techniques in a large eBay-like platform for a niche market...when the site previously did everything over direct user email...for over a decade. Good times.
In the age of Twitter and Web 2.0, we've started to see a lot of websites drop the standard www from their domain names. This could simply be a product of people following trends or just trying to be a little different, but the real question is "What are the drawbacks?"