Our machine rings 6 times before answering - long enough for DH to get to the phone. We had caller ID. Now we have U-verse and the ID shows up on the TV screen.
Most of the telemarketer/politicians ring 3-5 times and hang up. Some hang in and start their automated sales pitch as soon as our machine says "Thank you for calling..." so all we hear is the tail end of their pitch. Others hang in and cut off without leaving a message as soon as they hear our machine.
We don't even try to pick up the phone anymore since at least 95% of the calls are of this type. If they don't think we're worth a message, they are most certainly not worth any effort on out part.