How successfully are automated systems used?

I was wondering how many of you have had success using automated systems?

And is the demand programmed systems trading increasing?

As yet most systems fail. They can't cope with the changing market conditions. Perhaps there are some that can be profitable but they seem to be used in secret so the average Joe won't get near them.

Lots of false claims of profitability to discard.
One day maybe somebody at home or wherever will find a way.

Are you using systems already created or one that you will develop?
Either way, you need to focus on data quality when you first start....wish someone would have told me that.