From January 2017, the Chrome web browser will start labeling sites which collect passwords or credit card details as Not Secure.
If you run osCommerce and you don't have a secure certificate for your domain you are in danger of losing sales. In fact, you will lose sales unless you act.
In the future, Chrome will mark entire HTTP sites as non-secure, so now would be a good time to ensure your domain is future proof and make your whole site HTTPS. The argument that "my site will be slower