Find the ones you reached, the ones who intuitively understood and accepted and adopted Zotero.
They might be the seeds of success you build around, the ones who help promote the product.
Even if it is no more than successful engagement with one, then it is still a success.
Are there any significant decision-makers you can approach?
You can approach on the basis of cost reduction (did we mention it is free?).
You can approach on the basis of owning your research efforts and take it with you.
You can sell it on the ease of supporting collaborative efforts.
Given the nature of the web2.0 tools social nature you could integrate it into the writing lab.
Reach out to the younger generation.
Approach the professors who teach the Research classes, they reach broad audiences.
Just some thoughts.
Good luck, this is an effort worth expending.