On the good days, I place when I have to and run it out when I can.
On the bad days, I place when I can and run it out when I have to.

I tend to be a fairly bold leader. I don't take unnecessary risks, but I will take some if the time is right. I can lead at a moderate grade for myself fairly quickly with a minimum of gear, but as things start to get harder I put in more gear. Perhaps this is a common trait for everyone and 'run out' just depends on how strong a person is. Also, if the rock is a little more insecure then that changes everything. If the rock is loose or whatever then it is scarier to run it out. Or if it is wet or has been raining recently. I find it far easier to run out even hard terrain as long as it is secure feeling. hell, I'll even skip primo gear placements in favor of speed on looong multi-pitch climbs. e.g. 15 pitches or longer. they say that speed is safety and I agree. You HAVE TO get off big climbs before that storm rolls in or before night time. Also, if I have a really good piece, then I can run it out a lot farther after that because I know that somewhere down there is a bomber piece that will stop me. Falling onto the belay is a whole different story. Also, jeapordizing your partners is a bigger deal than simply taking a risk for yourself. If you get hurt on a long climb then somebody has to deal with you. I also like to do highball bouldering as a way to practice my head. I find that if I can keep it together on a desperate highball then I certainly can deal with a little run out on a lead. at least then you are not too worried about hitting the ground. Of course hitting a ledge is a different story. that could be as bad as hitting the ground. If you think about it, the ground is basically like a very big ledge so what is the difference? Also, the person belaying me makes a big difference. I have climbed with people who are not as good as me who actually SCARE me when I look down even if I'm not runout. Sometimes I'd rather be free soloing which is something I do with a significant amount of self-confidence. I would never recommend free soloing for someone who is not into it or who is doing it for the wrong reasons, but if you really want to it sure makes running it out seem pretty mellow. I have even free soloed short 5.12's!!! If your an aspiring runout type climber I would recommend a technique that I picked up in SoCal. We would pick a climb and do it a bunch of times each time with progressively less gear/bolts. Eventually we would be able to climb it with hardly any gear at all and then only at the hard parts. Eventually you learn when you do need gear and when you don't. If you place just one piece before the hardest moves and none in between then you'll use WAY less gear and end up climbing WAY faster. I guess it is just up to you how you want to do it. For me, I'll run it out any day!