I'm going to have to agree with nacht that i see what you're saying but can't bring myself to believe it.
I agree though that people can be addicted to love in a similar way as drug addicts.
But there's an underlying reason for everything we do. So I can't agree with your whole 'doing something for no reason is true love, and doing stuff that will give yourself pleasure is not' thing. Everything you do for that person can give you pleasure or prevent unhappiness in some way, even if it's only you doing something to avoid having an argument. If making them happy makes you happy, then anything good you do for them is also bringing you pleasure; I don't really understand your idea of doing something for them that has no positive effects for you.
I also have to agree with nacht that the definition of love varies from person to person. So I suppose your idea is a valid one, even if I don't necessarily agree with it.