I think USA was pretty unique with free local calls and hence why the scene took off big there. In the UK* we used to have to wait till 6pm for the price to drop from 5p a minute to 1p so internet usage and BBS prior was pretty constrained - the fear of 0345 usage on the bill was a constant fear that shareware mail order lasted into late 1990s. Broadband was also way behind, I think it was 2002 before we got 512kbit. (* there were pockets like Hull that was an exception I believe).
I don't recall free calls exactly. In my area we had band plans - there was an A, B and C band that had different rates. The A band would have a connection fee (1 cent? 5 cents? can't remember) and no per minute charge. The other bands charged various rates per minute.
Most people spent most of their BBS time in the A band obviously. That had the effect of having most of your users being very, very local to your BBS.
It was different in every state. When my parents moved "to the country" they made sure they were in the Minneapolis calling area, but it didn't occur to them that the local town where I went to high school wouldn't be in that area. As a result I could call some people who lived 70 miles away from our house at no additional charge, but neighbors just 5 miles down the road who I went to school with were not a free call.
One place I lived in the 80's, we had free phone calls within our phone company. So it was most of our county, parts of neighboring counties, and a county in a neighboring state.
You didn't even have to dial the full seven digits to make the call if it was inside the local telco. Just the last five numbers.
