The Baal Shem Tov insisted that when you do a favor for another, there must be no strings attached and no expectations.
Of course, you want this person to become a better person, a more spiritual person, to fulfill the purpose for which this soul came to earth by learning Torah and doing mitzvahs.
And of course doing someone a favor is the best way to get that happening.
But when you do a favor, it has to be just for the sake of doing a favor. Unconditional love.
And that is the only way that love can have its effect.

I like to be nice, kind, and loving toward humankind. And when I get the chance to help another with an issue I like share my show my love by giving them help, advice or whatever I can do to help with their needs. I like to think my kindness will rub off on them and they'll do the same for others, or maybe become more thankful to G D. But no matter what happens in the end and I don't receive a reward or they haven't learned how to do unto others; I tried to do my best and hopefully the next time around it may be a win win situation, especially for them.