I have mantained a site which receives over 1500 visitors a day, on a medium server, without any problem at all, this included a mysql backend as well.
80 visitors a day is really nothing to fret about.
You should be ok even if your traffic muliplies by 10,000 to 20,000.
Apache and MySQL are supposed to be capable of handling 150 - 300 connections at a time.
So:
60 seconds X 60 minutes X 24 hours = 86,400
86,400 seconds in a day, a decent server on a good network connection should be able to handle :
12,960,000 - 25,920,000 connections a day, as long as the code is good and efficient.
