The main concept was to make a bound oscillator calculate with a formula that places emphasis on the mean averages. Ideally this would mean that the oscillator won't have a tendency to swing into overbought/oversold condition and cause whipsaw. Using log is a way to increase the signal to noise ratio, with the regular MFI still plotted.
This indicator is best used in confluence with price action swings, where volume would normally be the highest.