I haven't done it for many years, but I was extremely happy with the results. I can't recall the specific percentage of people that hang up when they get an answering machine, but it's high. This was back in the days when pagers were popular. LOL! This is how it would work:
In the morning I would forward my number to the answering service. Their computer would tell them it's my number being forwarded and they would answer however I wanted them to. They would take the message and send it to me via a pager text. I would get the caller's name, phone number and why they called. Often if I could hear my pager, I could read it and call the caller back within a couple of minutes.
Since many people do hang up without leaving a message when they get an answering machine, having someone answer your calls only means more $$ in your pocket in the end. What do they do after they get an answering machine or voicemail? They call someone else!
By all means, use a service. It only makes sense. We spend a lot of money in our marketing campaigns and different advertising media to get our word out... and to have all that come up to nothing by not picking up the phone live is not a profitable activity to partake in.
Keep On Rockin'!
StihlRockin'