I have spoken extensively about how I use eBay as one of my primary sources for Amazon FBA online arbitrage stock. There are so many opportunities to buy unwanted items for cheap and sell them for profit over on the world'a biggest marketplace. I also sell through eBay too. Being on both sides of it, I understand the frustration of getting no feedback from a buyer, and the annoyance of a 300+ backlog of things you need to give feedback for.
eBay sellers need positive feedback to show eBay that they're delivering a strong service to their customers. Receiving a high quantity indicates that they do this consistently, so buyers should feel confident that a purchase will result in a swift transaction.
For eBay buyers, feedback is far less important. However, a 100% positive record shows sellers (particularly those doing collection only listings and selling expensive products) that they're selling to a trustworthy user of the site.
Back to that question of when you should give feedback. Does it matter? Does it make a difference. Let's deep dive on both sides.
As an eBay Seller
When you're selling on eBay, you have to put up with all sorts. The odd questions, the delayed payments, the back-and-forths. You have one job: remain professional. It's as simple as that.
When you're selling on eBay, as far as feedback is concerned, you have to make the first move. Don't wait on them to give the feedback, just do it once the payment clears (perhaps at the end of each day or week). By giving feedback to them, you greatly increase the chances that they will reciprocate. They can see from their side when they have.
Depending on how convenient it is for you, you may also want to drop them a message saying you have done, asking to confirm that the delivery arrived OK, and drop you some feedback too. One message will do. You've got better things to do than to request feedback multiple times for one transaction.
So there it is: ASAP. Make it positive, and keep it moving. If they turn out to be a bad egg, report them. But don't dwell on those too much.
As an eBay Buyer
As an eBay buyer, you have the power. It would be nice if you used that power for good, by giving feedback when it's convenient for you. No pressure at all; it's just nice when you do.
When using eBay to buy stock for business (like I do), sellers might be doing dozens of transactions a week. Absolutely loads, among which there will be returns. In this case they haven't got time to give feedback the minute they've unboxed their item. Sellers need to understand this.
It's convenient for me to give feedback monthly. At the end of the month I can assess all of the items that actually got to me and give feedback accordingly. For the transactions that weren't as smooth (incorrect descriptions, late despatch etc) I just skip over them). I'm sure other buyers will do the same.
Some sellers are too pushy and it's off-putting. I had one that sent three messages for feedback after having seen the tracked shipment had arrived. Some buyers can't accommodate quick feedback turnaround.
Buyers, give feedback when it suits you. At least monthly is polite.::::::::::::: - Chiino I don't do comments around here, so let's keep the conversation going on Twitter. If Twitter's not your thing, give us an email.