There are 2 ways for eBay to know that an item has shipped:
1) The seller prints a shipping label through PayPal. In this case, PayPal's computers communicate with eBay's computers and the item is automatically marked as shipped.
2) The seller goes into eBay and manually marks the item as shipped.
If the seller buys postage directly from the Post Office, or anywhere else outside of PayPal, then PayPal and eBay have no way of knowing this unless the seller tells them. Many sellers do not take the time to "mark item as shipped" manually.
How long has it been since you paid for the items? If it is still within a reasonable length of shipping time, then don't worry, the seller probably did ship and your items will show up.
Did the seller tell you which shipping service he used, and how long it usually takes?
If it has been longer than a month since you paid, protect yourself by filing an "Item not received" claim before Day 45.
