I get emails from both every 6 month (and tell them each time to come again 6 months later still, as I continue to run my own business). Two friends of mine, f

I get emails from both every 6 month (and tell them each time to come again 6 months later still, as I continue to run my own business). Two friends of mine, fine engineers with background in database systems and large-scale distributed systems, have got offers from both and had successfully played one off the other. One of them ended up in Facebook and the other one in Google. It's a war, no doubt.