Please Note: while eBay allows for near real time listings processing, - Amazon API uses queue system. This means that all requests sent to Amazon are queued and processed on a “first come, first served bases”. So it is advisable to submit information to Amazon in batches (i.e. not product by product). Also with Amazon there will be always slight delay before M2E Pro confirms successful synchronization.
The Amazon servers response time depends on Amazon system load at the moment of request.
Normally, it is 5-15 minutes, but may take longer ( i.e. hours) if Amazon system has some temporary issues.