In APIs and the Growing Influence of Developers I mentioned the bottom-up sales and adoption model. That post, naturally, was focused on developers, but I said that the model can apply equally to any type of "rank & file" users.
I was flipping through Salesforce.com CEO and founder Marc Benioff's book, Behind the Cloud, and came across the following passage, which is a good (and classic) example of how the model works well with products targeted at business users:
[Sales executives] Jim and David had been with us for only a week or two when an incredible opportunity unfolded at SunGard, a NYSE Fortune 1000 company. Cris Conde, who had just been promoted to CEO, was looking for a way to integrate the data systems giant's eighty different business units and saw CRM as the "unifying glue." The possibility of our biggest customer to date, and the thousand-user deal David had guaranteed, was right in front of us. At the time, SunGard's various divisions were working on myriad systems, but Cris noted that salesforce.com was the only one that was spreading virally. "The sales people were buying it on their own credit cards and going around their managers to purchase an account," he said.
That "vote" from the users was significant to Cris, and meeting with him to discuss our service's capabilities not only yielded our biggest customer at the time but also helped build a blueprint for selling to all enterprise companies.
Salesforce.com, as you may well know, went on to become the world's first $1 billion pure-play Cloud/SaaS company.