I assume you mean automated systems, not paying someone to answer
emails versus answering the phone.
It comes down to implementation. But don't expect more than a 10%
drop overall. And that is if you've done really well.
There are a lot of reasons for this, but the primary one is that if
you answer every possible issue on the site, it becomes hard to find
the right answer. And if you only answer the big ones, you still get
all the questions you didn't answer.
On top of this, there are many reasons someone needs to talk to a
real person. Not the least of which is trying to get a better deal
through haggling. People will always want the chance even when a
company really and truly doesn't budge from posted prices.
There are a few theories out there that could potentially eliminate
all standard questions from phone costs. But they all still require
the users to: Come to the site, Bother with the system, Be self
That is a lot to ask from your users and only the middle one can be
fixed. (By not posting your phone number until they have attempted to
use the system) But it comes at the cost of potential business.
Until AI gets to the point where it can parse natural language,
preferably vocally, customer service is going to need humans on
If you aren't a large company, you likely won't save enough by
building a system to account for it.
Out-of-box solutions often pay for themselves, if only due to their
low cost. However, they still require training the system to know
what questions to answer.