I like the AGPL for this. While it technically allows commercial endeavors, it forces the consuming software to also be licensed under AGPL if the software is considered "linked". Since businesses don't want to open source their core products, this encourages purchasing alternate licenses.

Unfortunately the AGPL has a chilling effect on using the software at all (see RethinkDB). I suspect the same would be true of any almost-but-not-quite-OSS license.