Proliferation of Blog Crawlers

The traffic to my blog has doubled in the past two months.  While some of that is due to new readers and subscribers, good part of that traffic is due to blog crawlers.  With the smell of money in the air, I am afraid we'll be seeing an explosion of blog crawlers in the near future.

How long before only a tiny fraction of the traffic is actually read by a person?  How long before the blogosphere is swamped by convenience-driven waste and greed-driven abuse?