Let's be realistic. Your run-of-the-mill researcher has no business expecting that the genetic test he just ordered will bring contacts with actual relatives.
Sure it happens. There are success stories. Adoptees find someone who tests as a cousin and that gives an initial lead where nothing was known previously. And occasionally a "new" "close" cousin will pop out of the woodwork.
But most genealogy researchers will already know their first and second cousins and often some of the thirds, and the ones who aren't interested in being found aren't usually the ones out there taking Family Finder tests. (And don't get me started on those who test but do not list their ancestral surnames!)
My cousin Sam did a Y-37 test and found a grand total of three matches. His haplogroup is J-M172 and his three matches are at a genetic distance of two, three and four.
My cousin Leonard (E -L117) did a Y-37 and has five matches at zero genetic distance (two of them from one family) and ten with a genetic distance of one - this with a surname which we know goes back three hundred years. There is no one close there either and none of his matches shares that common surname.
Aunt Betty (H10a1b) has nine MtDNA matches, including three zeroes, but not a one with a Family Finder match at any level.
My cousin Joe (K2a2a1) has eighty-two MtDNA matches with zero genetic distance, but only three Family Finder matches among them - and they all appear remote.
I have over seventy suggested second-fourth cousins and over six hundred suggested third-fifth cousins - aside from known family members - and that is after Family Tree DNA has invoked their magic algorithm that supposedly accounts for endogamy. WHO ARE ALL THESE PEOPLE? And more important, where are all the real third-fourth cousins who are surely out there someplace?
What all this overlooks, of course, is the perspective of timing and numbers. I did my Full MtDNA test (U1b1) and at the time I had six matches with zero genetic distance and one match with a genetic distance of one. Now, four years later, I have fourteen of the former and four of the latter. Essentially that means that when I joined FTDNA, there were seven matches "waiting for me." And my time waiting for new matches has brought eleven more.
I started with about 2200 matches on Family Finder three years ago and now I have 4471. My matches have doubled in three years.
If we look ahead another ten years, my matches could increase say three or fourfold. From that vantage point, the vast majority of my matches will not be people whom I found waiting for me, but people who found me waiting for them.
Sam has three matches, none closer than a genetic distance of two, but ten years from now, he may well have a dozen of more, including one or two with zero genetic distance. This is particularly true of people who are part of non-American populations therefore less exposed to the idea of genetic testing. Here in Israel, genetic testing seems to have a very small following among the veteran Ashkenazic population, so many of our cousins may be late coming to the game.
So the truth is, the realistic view is that with only five years of autosomal testing in the various companies' databases, we should not think that we are testing to find our relatives. We are testing so that when our relatives test someday, we will be there waiting to be found. In the meantime, we check our new matches every week or two. That "someday" may be this week.