Earlier quoted context omitted.
You create a new bitcoin address for every transaction. Some money goes to the actual recipient, and the "change" goes back to your new address. In addition, you can attempt to "launder" bitcoins by executing bogus transactions from yourself to yourself. Posting a static bitcoin address on your website and saying "send money here" is not considered best practice.
> "Posting a static bitcoin address on your website and saying "send money here" is not considered best practice." Can you explain why?
It breaks anonymity. Transactions are public and that static address is public, so anyone can tell how much money that static bitcoin address has received.