This Yahoo thing is urban legend for now. Yahoo resigned with Google late last year.
Ink is important for MSN searches... so if you had good msn from LookSmart and see the searches dropping off it would be an idea to do PFI at ink.
The best way to get free Ink is to find sites that are not paid that have good pacement and do a link exchange if you can.
To see if it is paid do a rollover of the link or a properties check.
If you see this
http://rdrw1.inktomi.com/click?
it is a PFI.