How do you maintain a track of a link expiring on your directory ( for a duration linking like for 6 months or 1 year) Is there any automatic process which will remind us and to the link submitter for renewing it ?
Good question, I've been thinking about this too. For the time being I'm manually writing them all in a diary.
Algorithmically, when you get a payment, you can set an EXPIRY value to track how long the payment lasts. However, if you get a payment before a previous payment expires, you must ADD the purchased time to any remaining time or you will "cut off" existing paid time. Anyway, if you get the right date in a database, you can run queries to detect items expiring soon in order to send an email (perhaps a week or two in advance). You can also run queries to remove the featured listing or status automatically after the expiry date. Just be sure to set flags of some type so you don't send repeated email messages or try to reprocess already handled status changes.
Paypal i think does send out email that user has cancelled the subscription cause phpld2 uses paypal subscription method, hence on due date paypal automatically deducts from users account the required money, so keeping track on paypal email can also help.
One more question regarding "Featured Links" When the link expiree, i.e. if the payment is on yearly bases, does it became inactive or it is removed??? Also, do the admin and link owner get any notification about it??