WebRequest.Count Property (Bing, Version 2.0)
Specifies the number of results to return per WebRequest.
If the number of results per page requested in the WebRequest.Count field is greater than the total number of results returned in the WebResponse.Total field, the number of results per page will be equal to the total number of results.
The minimum value for Count is 1; the maximum value is 50. If a value outside this range is specified, the Bing API returns an error.
Search results are limited to the first 1,000 results. This means that the total of WebRequest.Count plus WebRequest.Offset should not be greater than 1,000.