I operate a large established (2.5 years) forum with over 20,000 users. It is NOT listed in the Yahoo Directory however. Should I pay the $300 a year to get it in there? What would I see in terms of benefits? Thanks!
Directory traffic would make a listing well worth the 299 price, provided that you are placed high up there in the category, good title, description and you are listed in popular category and it's hard to find any category with all the above. It also doesn't ensure that your site will be accepted, so if you get rejected you just wasted money that could went for something else.
Google (And Yahoo! seems not to care much about it too.) doesn't value Yahoo! directory listing like it used to. Even if Google still looks highly of a listing in Yahoo!, you could get a listing in many other directories that require no payment for submission and with all those directories together would beat out a Yahoo! listing. You also have to use your site's title in the listing, which kills the reason of submitting even more IF you are doing it for search engine ranking.