This invention relates to a method, a device, a server and a system of/for peer to peer transfer of content. Said method includes the steps of receiving and transmitting, from a first device (11), a first request with a first selection criterion for a first content to a server (18) or to a second device (12); transferring the first content satisfying said first selection criterion to said first device from the server, when said server previously has acknowledged said first device as a legal recipient of said first content and in case said first content is available only on said server, and noting that said first device subsequently has the requested first content available for other devices (14, 15, 16, 17); or re-directing said first request to a third device (13) on which the server knows that the requested first content is still available and transferring said first content satisfying said first selection criterion to said first device from the third device; or transferring the first content satisfying said first selection criterion to said first device from the second device, when said first content is available on said second device, and informing the server that said first content has been transferred to said first device from said second device; and rewarding the one of said second or third device from which said first content was transferred to said first device, when content was transferred from one of these; and charging said first device for reception of said first content. This enables for download, upload and sharing of legally protected paid-for content.