Personally, I do not like the idea of advertising by a sponsor. With sponsorship, particularly narrow sponsorship, comes the expectation of the sponsor (sooner or later), which is not necessarily unmanageable, but inevitably causes strife.
Maybe the group could consider a more broadly based revenue stream such as a ‘directory’, where a range of individual suppliers can be listed in return for a small fee, which cumulatively pays the groups.io site fees. This model is possibly less likely to suffer from the demands of a single large sponsor, may be more robust in terms of cash-flow and would possibly be more useful to owners.
Bill, are we considering the implementation of this revenue generation idea immediately?