Some people just don't give feedback. Some people do it immediately upon receiving payment. Others wait till the OTHER persons leaves feedback. Others wait a bit and then leave feedback.
As a buyer, it's simple. I leave feedback when I get my stuff and check it out to make sure it is all hunky-dory.
As a seller, I debated this issue for a while and decided what I thought was best for me.
I am a firm believer a transaction is NOT over until the item is shipped and received and the buyer is content with their purchase... and if they are not content, then until everything is resolved as best as possible.
In the "your-item-has-been-shipped" email I send each of my buyers I indicate that I'd appreciate if they'd email me when they receive the item to let me know they received it and are satisified. I indicate if they prefer to leave positive feedback instead of writing, that is fine too. I also indicate in that same email to please email before leaving feedback if there is ANY problem so we can work it out.
If I do not hear from them or see feedback from them within 2 weeks of the ship date, then I go ahead and post feedback. My rationale is that 2 weeks is usually plenty of time for the item to have arrived and been inspected. Sometimes I notice the buyer will THEN post feedback... one of those who likes to wait for the OTHER person to leave feedback first... which is fine.
It's an extra administrative headache for me to do things this way. Leaving feedback immediately upon receiving payment is easier, but for me it just doesn't feel right. I use a spreadsheet to keep track of all my sales, and there is a column in it to remind me to leave feedback.
Occasionally I will even make the effort of writing to make sure they received their item... especially if they were someone I'd exchanged a few pleasant emails with. But most of the time I assume after 2 weeks, no news is good news.
So... whomever posted this thread (sorry I've forgotten since I started writing this), hang in there. You may still get feedback from some of those sellers. If not, you will from others.
Good luck.
diva (aka Dag)