Maybe revenue sharing from advertising? Or maybe Rimm will kick back money to FB forZ10sales created from Facebook? It is a good idea for the two to team up on joint projects that are win win. As far as FB buying RIMM the best way to gain a foothold without spending hundreds of millions would be to buy out of the money calls. If Rim nosedives then they lose the premium they paid for the calls. If the price of the share surges, and if the total number of call contracts would represent 5% then FB would make a ton of money on their investment.
If FB needs to buy a large number of call contracts they could try contacting Fairfax or any other large institution who presently own a ton of shares.
Fair fax would earn a healthy premium. And FB's buying price of shares would be locked in and then if FB wanted to offer to buy RIM Fairfax Financial would be in a perfect position to broker the buy out offer.
One thing for sure, FB wants to improve their bottom line. If both companies are smart they could both make a ton of money while maintaining their independence