I know this is old school, but do you realize SE's still look for this file?
robots.txt
I have proven it gets better rankings by publishing two identical sites with similar URL's and the one with the robots.txt consistently ranked higher then the one without it.
Here is a good example to use:
----text begins---
Disallow: /cgi-bin/
Disallow: /tmp/
User-agent: *
Allow: /all
Allow: /
User-agent: Mediapartners-Google
Allow: /all
Allow: /
User-agent: Googlebot
Allow: /all
Allow: /
User-agent: Adsbot-Google
Allow: /all
Allow: /
User-agent: Googlebot-Mobile
Allow: /all
Allow: /
---end text---
Simply copy that to notepad, and FTP it to your website...it does help!