This interesting post by Guillaume Lovet, spotted by Ian Grigg, explain the business case for criminals obtaining personal data for bank accounts.
All of the following phishing tools can be acquired very cheaply: a scam letter and scam page in your chosen language, a fresh spam list, a selection of php mailers to spam-out 100,000 mails for six hours, a hacked website for hosting the scam page for a few days, and finally a stolen but valid credit card with which to register a domain name. With all this taken care of, the total costs for sending out 100,000 phishing emails can be as little as $60. This kind of ‘phishing trip’ will uncover at least 20 bank accounts of varying cash balances, giving a ‘market value’ of $200 – $2,000 in e-gold if the details were simply sold to another cybercriminal. The worst-case scenario is a 300% return on the investment, but it could be ten times that.