Back a ways, I noted the bizarre total number within my circle in Orkut--more than two million at the time--and that the number did not decrease significantly when I cut my number of "friends" from 21 down to 12.
One who shall go unnamed (why cause him grief?) sent email with an interesting suggestion: The number being reported is roughly the total size of Orkut, and has nothing to do with your own "six degrees of separation."
Just now--with the two million+ having grown to three million+ in the interim--I did a little test of that. I deleted all my "friends" with two exceptions, each of them people with only 20+ direct friends in their own circles.
As I checked periodically, the total number varied, but in no meaningful manner. That is, it started at 3,021,371. After I deleted four of the twelve, it went to 3,018,027. After deleting another four, it went to 2,966,236. And, finally, after deleting all but the two most selective friends in the list, it popped up to 3,023,708--the highest number I've seen.
First, my apologies to anyone who actually uses Orkut, considers me a friend, and wonders where I've gone. Nothing against you: I consider all of the dozen to be friends, and just eliminated 10 of them in a spirit of inquiry.
Second, my opinion is that the number within "my circle" in Orkut is meaningless--that final behavior, jumping up when I deleted a couple more people, can't be explained in any rational manner I can think of.
Third, I've unbookmarked Orkut (since I can't figure out a way to actually delete my "membership"). I do believe social networking software, at least within the business world, may have its uses. I don't believe Orkut has any uses for me, and there are other better ways to waste time. (Like writing journal entries...)