I have a small retail business in US. I receive phone calls from
customers every day from my yellow pages ad. I need to know how many
calls I get every day on my land line shop phone. I am sure there must
be electronic devices that counts calls . Are there such devices that
counts incoming calls and who sells them? Do phone companies provide
this service for land lines?
thanks,

I believe most caller ID units include a call-counter. I have a caller
ID device that I bought for $5 at Big Lots, and it displays the number
of calls that have come in (up to a maximum of 99).