arodland, isn't the converse true? The more users of gnutella there are, the more non-sharing users there are in your gnutellanet horizon? This means that you need a larger horizon and bigger TTL.

Ignoring the other issues that make parts of my statement above "false", when there are more users, the existing uploaders are swamped with requests. So, you need a bigger list of search results in order to find the few uploaders that still have bandwidth for you to download from.

The default of gnutellanet clients is to NOT share files so most people find that to be their most convenient setting and leave it that way. Perhaps there can be some other ways to encourage the sharing setting to be enabled somehow.