For me, any such number is an artefact of the data -- they've included things like the name and demographics of the idea's author, which will be clearly useful

For me, any such number is an artefact of the data -- they've included things like the name and demographics of the idea's author, which will be clearly useful in practice for a "Show me more ideas like this" application, but which will only be misleading if trying to study the nature of "idea space".