Capital One has long offered this promotion. This new one is scheduled to last until 4/30/2013, but it will likely be extended. Similar Capital One promotions
have been targeted and required the original mailer. So your miles may vary (YMMV).Capital One promotion page link
Here's what is required:
1) Open a Capital One Business
2) Deposit at least $3,000 within 30 days of account opening and make one online payment.
3) $300 credit to your business checking account approximately 10-12 weeks after the end of the promotionAvailability
It requires that you print the coupon and bring it to your local branch. Capital One has branches in Texas, Louisiana, New York, New Jersey, Connecticut, Maryland, Virginia and Washington, DC.