This whole thing reeks of taking the easy way out and dumping the problem on the user. Why can't you analyze usage patterns in a controlled environment to identify the typical number of page loads?

You end up at a statistical answer like 20 hits to our home page equal 6.3 users, statistically speaking.

Why care? Despite all the pearl-clutching, knowing how many visitors you have is only marginally useful data at best, so it doesn't need to be precise.

Are you being disingenuous? Do you really think that commercial websites can operate without knowing if their visitor count dropped by 15% over 30 days, or what their visitors come looking for, or through which channels they find and buy your products?

None of that requires distinguishing users from hits, definitely not beyond the guesses you can make from server-side logs.

if there are 20 different user agents, i would count that as 20 separate users.