make an app like PayPal, then you can go ahead and implement that. All it would take is a little effort to get some money flowing from the system instead of trying out different payment systems for months before deciding to make an app like PayPal what works best for them. When I ask why people use these solutions (e-mailing developers or asking others how they make their sites look nice), my question usually gets bounced back saying 'the reason we've made your site special?' This seems strange on two fronts: first, most companies are already familiar with using PHP5's built-in templating engine by now; so maybe someone didn't do all this research when choosing between something more to use.