It measures some combination of how general an essay is, how early it was written (I usually add these links when I first write something, so most links are only backward in time), how much I like it, and sheer randomness (at least half the time I don't bother to add crosslinks).

Larger numbers of outgoing links probably don't imply recycling. If anything it's a sign I think an essay is good and will get lots of readers, so it's worth trying to spread that traffic around. (These predictions are often wrong, though. I find it practically impossible to guess which essays will get lots of traffic.)