The ShowMoreResultsBox functionality allows you to load portions of items to achieve a faster loading speed. For example, you could add 20 items per a request.
Example
After clicking on the ShowMoreResultsBox(
), the next 20 items will be added to the Items list.
A live example can be seen at:
Autocomplete Callback From Dictionary
Also, you can achieve paging with the ShowMoreResultsBox. An example can be seen at:
Paging in RadComboBox' Load On Demand