How many times do you call/leave voicemails on a lead?

I leave a voicemail once, and as you said they hardly ever call back. The reason I leave one is so I can keep calling, later that day, or whenever the receptionist/sec says they will be in again and try to get TO the DM and say "I left you a vm the other day, and didn't hear back, I'm sure you're busy, but I wanted to catch you so we can set up a time to talk." Or something like that. Saying that you LVM for them, if they are like most people, will put them on alert that you took the time, and that you've gotten through the gatekeeper, so most people will agree and say "yes, I'm swamped." That's where I say "it's ok, when is a good time for us to talk for about 5-10-15 (whatever I need) minutes? How about Tuesday, do you have a few minutes then?"

As for those that don't return VM's and I can't reach. I'll usually try to reach someone for a week, off and on if it's a good lead...after that, I'll move on if they aren't in, unavailable, and otherwise NI.

That's what I do, just so you have options.

I leave one voice message. I have not seen any advantage in leaving many messages. Maybe under certain circumstances, for instance if I was referred to them, I'll leave it a second time.