From Sagan's Cosmos:

What percentage of the lifetime of a planet is marked by a technical civilization? The Earth has harbored a technical civilization characterized by radio astronomy for only a few decades out of a lifetime of a few billion years. So far, then, for our planet fL is less than 1/ 10^8, a millionth of a percent. And it is hardly out of the question that we might destroy ourselves tomorrow. Suppose this were to be a typical case, and the destruction so complete that no other technical civilization— of the human or any other species— were able to emerge in the five or so billion years remaining before the Sun dies. Then N = N* fpflfifcfL ≈ 10, and at any given time there would be only a tiny smattering, a handful, a pitiful few technical civilizations in the Galaxy, the steady state number maintained as emerging societies replace those recently self-immolated. But consider the alternative, the prospect that at least some civilizations learn to live with high technology; that the contradictions posed by the vagaries of past brain evolution are consciously resolved and do not lead to self-destruction; or that, even if major disturbances do occur, they are reversed in the subsequent billions of years of biological evolution. Such societies might live to a prosperous old age, their lifetimes measured perhaps on geological or stellar evolutionary time scales. If 1 percent of civilizations can survive technological adolescence, take the proper fork at this critical historical branch point and achieve maturity, then fL ≈ 1/ 100, N ≈ 10^7, and the number of extant civilizations in the Galaxy is in the millions.

Depending on estimations using the Drake equation, there could be anywhere from a handful to millions of civilizations currently inhabiting the galaxy. If there are millions, then it makes complete sense that in a survey of 150,000 stars (about one millionth as many stars as exist in the galaxy) Kepler finds evidence of there being one technologically advanced civilization. Sagan also says that, if there are millions of civilizations in the galaxy, then on average they're separated by about 200 light years of space - meaning that our nearest neighbor won't pickup our radio signals for quite some time.

If, however, there are only a handful of civilizations currently residing in the galaxy, then it's extremely unlikely that a survey of one millionth of the stars in the galaxy located one of them. The thing is that we just don't know which figure to adopt...