The assetstore could have much more customers who would be able to dig much deeper into the rabbithole (and actually find more then the top ten of every section) if Unity would allow the assetstore to get indexed by google.
Right now the whole assetstore is simply not available for search, because you have this on every page:
<meta name="robots" content="noindex, nofollow">
Please paste this into google:
site:assetstore.unity3d.com
This is, what google knows about the assetstore and all of the assets you can buy there.
Not much.
You get no search enginge traffic for the assetstore.