Ok here it is again; Directory has 10,000 links, submission of 500 per week, alexa rating of between 100,000 - 200,000. When do you begin charging for submissions?
If one is going to charge best to do it from day one. Can't say if it would be worth anything to be listed in the directory you describe without seeing it. Right now we only know 10k listings with 500 more coming in per week. All that really tells me is that unless your exceptionally dedicated in reviewing those submissions and editing the submissions it is probably filled with un-edited spam and not worth paying to be listed in. Could be wrong on that because you did not note the site, but even allocating a mere 5 minutes per submission for review that would be about 41.5 hours per week to review and edit all those free submissions. Are you doing all that for free or are you just mass approving those submissions? Mass deleting? Or just letting them pile up? Those questions will provide the answer to whether a directory should be paid or not. Not the number of unedited listings one manages to collect or freebies one manages to give away. Again a quick look at the site would help others give you a real answer.
Yup, I agree too. It's hard to start charging once you've got a million of links in your directory since people rather pay for a link in a cleaner directory. Maybe you could set these free links to expire after a certain period and start accepting paid submissions only - just an idea.
Add paid option to see what will happen. If you'll get enough paid submissions per day to keep you happy, then switch to paid fastreplies
Start charging when your directory has the quality to make submitters willing to pay to be in it. This normally requires years of work and good editorial skills.
The best time to charge for submission reviews is when you are completely done populating each category by hand (yourself). Otherwise you will be left going back and cleaning up those freebies. It is reasonable to charge a fee for reviewing and maintaining your directory. Start out with a small fee which honestly will weed out a lot of the spam. Even $1 is a good start. Good luck!
if people find you advertise your directory at another directory, maybe it will more interest to pay at your directory... doing promotion and it will benefit all people that submit to your directory..
Why don't you try offering a link submission service. Charge $50 - $60 for it, you'll get people who don't know where to get it for less so you outsource it here for $20. As far as making money for your directory, have you every thought about doing cpa's? Many of them are simple 1 page surveys, people probably won't mind filling them out and you make your money. I never payed to be in directories because there are too many free ones, and I bet many others would be the same way. My 2 cents worth.