In every decently sized outbound calling campaign, the number one and number two most common dispositions will almost always be "No Answer" and "Answering Machine"...this is not unusual nor surprising...
What determines which of those two dispositions is on top, is the "dialing timeout" - basically, how long you let the phone ring, before dropping the call...
If dialing timeout is set too short, "No Answer" will be on top, as the system only lets the phone ring for a short amount of time before ending the call...this runs a very real risk of not giving the prospect enough time to actually answer, and also upsets the carrier algorithms as it indicates a calling party not truly interested in, or expecting to, make contact...
What you WANT to see is "Answering Machine" edging out "No Answer", which allows the prospect phone to ring long enough to reach the end of the road, regardless of the eventual outcome...
So, if your "No Answers" are regularly exceeding your "Answering Machines", we recommend strongly that you increase your dialing timeout to between 20 and 28 seconds...
This gives plenty of time for the prospect to answer, eliminates the short duration hangups, and prevents your customer's phones from looking like this :-)