The promotion is very simple, just go to the Electric Orange information page  and click the orange “Apply Now” button. On the next page, click on “Continue” and put in E7NSTND into the reference code box. Complete the rest of the application.
When your account is opened, you’ll receive an Electric Orange Debit MasterCard. You need to use it in “3 signature-based purchases within 45 days of account opening” to qualify for the $50 bonus. On the 50th day, the bonus will be desposited. A signature-based purchase is one where you need to sign for the purchase, rather than use a PIN. In most cases, it means you need to select “Credit” (instead of debit) when asked.
If you want to add a little more juice to the promotion and you aren’t already an ING Direct customer, you can apply for a savings account first using an ING Direct referral  first. That’ll get you $25 to start, then another $50 with this checking account bonus.
There’s no published expiration date.