Rate Limit Changes to Shopping, Finding, and Merchandising API
To manage your call limits better, eBay is changing the basis for rate limiting API usage for the Shopping, Finding and Merchandising APIs. Starting March 1, 2011, call usage will be measured by application instead of IP address. The call counts will be aggregated for your application based on the AppID used to make the request, rather than the IP address from which the request is coming.
What does this mean to you?
If your application is making more than 5,000 calls a day, go through the compatible application check to get your call limits increased to prevent any disruption to your application.