In life people tend to look at results. "People", I say, but not Hashem.
To wit; You set up a couple. They decide to break up after the first date. As far as you were concerned they could have gotten married and if they had wanted to, you would have been delighted. So they might well not appreciate your efforts but as far as Hashem is concerned, you made a shidduch! The "lomdus" is that if you tried to do a mitzva and due to circumstances beyond your control you were unable to, you are nevertheless credited with the mitzva. In our example you tried to make a match but due to circumstances beyond your control [he wants a taller girl] you were not successful. Count it!
So I have three shadchanim to whom I must feel gratitude even though I have not been married three times: The nice lady who set me up with the first girl I met [nice girl, bad date:)]. The first girl who set me up with her friend [ditto:)] and ultimately the nice couple who set me up with my wife. Some people I know have HUNDREDS of shadchanim. That's a LOT of gratitude.
Another example; You try to get someone a job. If they weren't hired that is not your fault - you tried. It is as if you were responsible for supporting this person's family for many years to come. Is that SOMETHING?!!
So sweetest friends - don't look at the results. That is in G-d's Hands. You do your part and let things happen according to whatever the mysterious Divine plan may be. Set up a couple. Help a Jew find a job, a house, a good life insurance policy, whatever. Just do GOOD.
But you knew that. Just giving a gentle reminder....
I now say my bedtime prayers and travel off to dream land but not before I wish you all a WONDERFUL night:-)!