Decluttering
Map decluttering is a mechanism where a large number of markers on a map are replaced and instead represented by a single marker. This is generally not recommended for use when displaying camera or Drive stream markers. Instead, the application should use a smaller marker, and allow clarification if a user selection is ambiguous (e.g., in a pop-up window).
Decluttering (not recommended)
No decluttering, as used by MapQuest
For very large geographical areas (e.g., an entire state or province), consider using a marker to represent each city or market, which, when clicked, would zoom in to that area's coverage.
City markers, as used by MapQuest