The draw back is that this plugin uses a 'paypal merchant ID' rather than a paypal account email address to connect to paypal. 'Paypal merchant ID's' are the old way of connecting to one's paypal account on a payment gateway. Now paypal can encrypt your email address address for better security. The problem of using merchant ID is that, if you have multiple emails associated with your paypal account, by using a paypal merchant ID you will have to change your primary email address just to suite the website for which you have installed this plugin. Paypal merchant account are old methods for sellers that just have one email associated to their account. Besides, many people do not even know how to find their merchant ID numbers. Even when you login into paypal it is not easy to find it. But here is a quick link to show you where your merchant ID number is. https://www.paypal.com/webapps/customerprofile/summary.view I would suggest modification for the plugin to use paypal email addresses rather than merchant ID. I still think for $20 this plugin is too expensive and should come free as an OXWALL core plugin and let developers extend on it.