The PayPal Adaptive Payments API enables you to send money in many different scenarios, from simple to complex. For example, you might build a small send money application for a social networking site or a robust payroll system.
The store owner (merchant) must have a PayPal Business account. Senders and receivers can have any PayPal account type. Senders and receivers are not required to have PayPal accounts initially. PayPal prompts a sender to create an account before a payment can be completed. A receiver must create an account to receive the funds after the payment completes.
Please see the following link for more information on PayPal Adaptive Payments:
https://cms.paypal.com/us/cgi-bin/?cmd=_render-content&content_ID=developer/e_howto_api_APIntro