Making a Shidduch

1)The Gemara in Shabbat (31a), according to which one of the questions that one is asked after his time on this earth is up and he is facing the Heavenly judgment is “ עסקת בפריה ורביה ” — “did you engage in procreation?” TheMaharsha comments: The Gemara did not say [that one is asked] “did you fulfill [the mitzvah] of procreation,” but rather “did you engage [in the
mitzvah of procreation],” meaning, “[did you take steps] to marry off orphans.”

Maharsha, Chidushei Aggadot to Shabbat 31a, 
לא אמר קיימת פריה ורביה אלא
עסקת דהיינו להשיא יתום ויתומה .
מהרש"א חידושי אגדות לשבת
דף ל"א. בד"ה עסקת

The Maharsha clearly understands that being engaged in the mitzvah of procreation means more than fulfilling that mitzvah by having children oneself; it includes doing what one can to facilitate the fulfillment of that mitzvah by others, by people who are less fortunate and who may never have the opportunity to get married and perform this mitzvah without the efforts of others. One who helps someone else get married and thereby enables him to carry out the mitzvah of having children is thus fulfilling this requirement of “involvement” in procreation;
And this is considered so significant a deed that it is one of the first things one is held accountable for when he leaves this world.

2)A Roman matron asked Rabbi Yossi how long it took God to create the world. He replied: “Six days.” She asked: “What has your God been doing since then?” Rabbi Yossi replied: “Making matches. This man to that woman, this woman to that man.” The Roman matron replied with surprise: “Is that all? Why anyone can do that!” Rabbi Yossi observed, “It may seem easy to you, but for God making a good match is as difficult as parting the Reed Sea.” But to prove her point, the Roman matron returned home and lined up all her household servants – 1000 men and 1000 women, paired them up and married them off. The following morning they returned to her, one with a black eye, one with a bruised face, one limping, and another wounded, each with its own misery and saying, “This one that you designated for me I do not want.” The Roman matron sent for Rabbi Yossi and said, “Rabbi your Torah is truth and it is beautiful and praiseworthy. You spoke well in all you said.” (Beraishit Rabbah 68 and Vayikra Rabbah 8)