I've always noticed that effort spent on google results in way more traffic than time spent on anything else, but maybe I'm missing something. PFI for search engines that send out robots seems like a waste of time. If you have a half decent site, they'll find you. If they don't, their index sucks and they are a waste of time.
I never got good results on goto.com back when it was cheap it was expensive. Waste of money for me (although I know it is worth it for some people). Google Adwords is an awful lot of work, that if spent on creating content will results in renewable traffic without extra effort. Waste of time and money for me.
But PFI is probably a good idea for directories and the like. As long as it's a one time thing. Are there any?
Who are the big players in PFI. Does PFI mean to you directories AND SE or only SE. Thank you.
I use PFI for SE's (Ink, Teoma, Fast) for a home page and category index pages. This particular site changes product lines two or three times a year and PFI has been invaluable to keep current results in the indexes and tweaking the pages as needed. Eventually other pages in the site are spidered and added so we end up with two or three well-ranking pages for our key terms; this is particularly true with Inktomi.