In Auctions:
The seller can look at each bid as it arrives and investigate the bidder. She can cancel any bid and Block any bidder.
However, most bids arrive in the last few minutes or seconds of an auction and there may not be time to investigate bona fides.
With Fixed Price listings:
The seller only meets her buyer when he purchases.
*She can cancel transactions for a very few reasons, some of which give her a Defect on her selling account (out of stock is a killer) and some of which don't (buyer request, problem with address).
The seller can set up the Fixed Price listing with Immediate Payment Required. The listing remains available until someone pays.
IPR is not available on Auctions.
With Best Offer:
These are only good for 24 hours.
The seller can refuse any Offer.
The seller can ignore any Offer.
The seller can set up a minimum under which Offers will be automatically refused.
The seller can Block any unwanted customer.
Best Offer overrides Immediate Payment Required.
Blocking Bidders:
Using her Buyer Requirements, the seller can Block bids from members with Unpaid Item Strikes **, no Paypal account (questionable now that Guest Buyers are a thing), and a couple of other less useful reasons.
Location:
A seller can set up listings to be invisible to bidders from chosen countries on the Advanced Sell Your Item form. Just saying you only ship to Canada doesn't do this.
Buyers with addresses in countries she does ship to can still bid and win, with the purchase being shipped to a freight forwarder (or the buyer's Auntie Sonia in Brooklyn) where the seller's responsibility for delivery ends.
Paypal.
I think Sellers can refuse payments from non-Canadian accounts. This is big with US sellers who are a paranoid and xenophobic bunch.
BTW- only about 15% of eBay transactions are now Auctions. And more than half of the customers are using phones to bid.
When you start listing, look at your items on a smartphone. You will be shocked at what your buyers do and don't see.
*Also available for Auctions.
**Highly recommended.
