So many beautiful girls around, so many bright smiles and shining eyes secretly staring at you! And the question is who to choose for dating... in the first place
A love detector also measuring feeling intensity would be very useful for making such a difficult choice. With its help you would be able to compare the feeling intensities for all potential dates and choose the one loving you the most - that would obviously be the wisest choice.
This love detector might be a visual one counting and analysing the number of unverba, paraverbal and behavioral clues revealing his/her attraction to you, or a chemical one detecting intensity of hormonal change through olfaction...
But who cares how it would work. I would pay any money for having such a device for detecting the girls most attracted to me