You can check the System Status if you have requested your photos to post or delete.  This will give you an indication of the traffic on the site and the demand on Facebook's Rate Limiting system.  Facebook only allows a certain amount of requests to be made every hour by third-party apps, like POP.  One item posting/deleting/or pulled Sold comment = 1 request. The System Status will show you if requests are "peaking" at a certain time.  If the requests are reaching their maximum, posting or deleting will be slowed to accommodate the traffic. 


The System Status page can be found under the Inventory tab in the left hand navigation.


Once your photos are ready to post you can look at the System Status to see that the number of items you have scheduled to post are in fact posting.  It will show you how many posting requests have been made, and if your items have begun posting. The System Status will also show you your deletion requests, how many deletion requests have been made, and the average time of the oldest request. 


This is a way for you to keep up on how the system is running and helps you make an educated decision on the best time to post or request your photos to be deleted. 

It is always a good idea to keep an eye on this page.