Sometimes it occurs that your own bank does not provide you with good merchant account services. In this case you will have to look towards another bank or maybe even a 3rd party provider.
To accept credit cards a merchant account is a must. It will help you to accept payment from all countries and in all currecies. So in short it will be like your offshore account which accepts all your payments on time and will charge you a small transaction fee in return for their efforts.
You can also open merchant accounts outside your home country(USA) and laws in these countries are very easy and flexible. With the help of offshore accounts you can invest in the capital markets of those countries without any fear of doing anything wrong.