The server then receives, from a client, a request for {HEAD ~ an advertisement} to display to {TAIL ~ the first user}, selects one of the other users having a friend rank satisfying a predetermined threshold, and transmits, to the client, an advertisement portraying the selected additional user 
to display to
The server then receives , from a client , a request for { HEAD ~ an advertisement } to display to { TAIL ~ the first user } , selects one of the other users having a friend rank satisfying a predetermined threshold , and transmits , to the client , an advertisement portraying the selected additional user
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH