not listed

yahoo doesn't crawl but google does

[vampke]

Hi,

I am new at the whole website building thing, so please bare with me.
I have good results on google for certain keywords, but I'm not listed on Yahoo at all. I don't understand this.
There doesn't seem to be a Yahoo-bot crawling my site, I have about 6 googlebots every day.
Why this difference? Does Y! only list you if you pay them?
I have the same question for overture: no bots coming from there either.
I have a few external links to my site that are listed in these search engines.

Thanks for the help!

Ciao