You may already have a database running your auction site. Suddenly, like when PayPal appeared on the scene, you might see a new payment opportunities that your customers may be using, but which you didn't know about when you designed your original site.
How do you proceed?
Let's think in simple terms with an auction site with the following fields in your database:
Now you suddenly notice something like MobilePay which is a mobile phone-based payment system in Denmark.
What you want is for your database to contain the following fields: