First, I'm impressed. But I'm having trouble believing that it doesn't cost much. Isn't that lot of bandwidth (getting pages and generating previews), especial

First, I'm impressed. But I'm having trouble believing that it doesn't cost much. Isn't that lot of bandwidth (getting pages and generating previews), especially if you are doing that on the fly? Or does your crawler generate and cache preview images? If the latter how large is your index? Is the monthly cost minimal simply because you don't yet have much traffic?