"First one's free," the classic phrase goes, and it can apply to all sorts of products and services, savory and unsavory. But some of the Internet services I've come to rely on the most are ones I discovered through a free trial or tier--and usually without the approval of my IT department.
At my last employer, my group was a tiny pool of tech-savvy west coast tech writers with an IT organization that was very east coast, careful to react, and deeply committed only to software and services with the Microsoft label on them. Meanwhile, we were constantly hearing about new services from sources and colleagues, and trying them out. It was hard not to become infatuated with some of them.
Take group communication. Our organization was happy to provide us with file servers and e-mail, but that was about it. Different groups bounced around various instant-messaging services (these were the days of AIM and MSN Messenger), but then we discovered Campfire.
Campfire was hosted group chat, with a free tier and some for-pay extras. It was pretty great, and all of a sudden we had a set of shared chat-rooms to use in coordinating our jobs. Our developers used Campfire's API to post status messages from our online publishing system in the chat rooms. It was pretty great. We upgraded to the paid version and I got someone at our company to even pay for it, making it semi-official.
You might say, in fact, that Campfire was Slack before Slack. (If you don't know what Slack is, the short version is that it's chat software. The long version is that it's pretty great chat software that can integrate with lots of different web services to provide a place for people in a workgroup to communicate, share files and information, and collaborate. In many organizations, it's rapidly turning email and instant messaging into old news. As someone who works from home for a few different geographically distributed organizations, it's both a social lifeline and an impressive collaboration tool.)
Anyway, the owners of Campfire were too busy focusing on Basecamp to really do much with Campfire. A new hire from a different company led us to HipChat, which we switched to eventually. But unbeknownst to me, a bunch of editors had discovered Slack, and thanks to its generous free tier, they had moved most of their discussions to that service.
I hear that story again and again -- Slack has grown rapidly by starting users out with that generous free tier--unlimited users, five external integrations, and a limited searchable archive. People try it out, like it, and it rapidly becomes indispensable. Sometimes the corporate IT groups hear about Slack long after it's colonized an organization. The good news is, Slack's a pretty great service that's working hard to appeal to the enterprise--and some of those Slack integrations with external services are mind-blowing--and many enterprise accounts will be happy to pay Slack's rates for the privilege.
And about those Slack rates: Slack's pricing is very clearly designed to support exactly the scenario I've outlined above. Most free tiers in freemium services are designed to give you just enough pain that you're forced to step up to the next level of service. Slack doesn't do that--the next tier up is $8 per user per month, a fairly large jump for a small business. (One of the small Internet businesses I work with would need to pay several thousands of dollars a year on Slack, which would immediately become the company's largest single expense!)
Slack does this because Slack isn't trying to build a business around getting small amounts of money from a bunch of small users. Slack's in this for the big guys--the companies that are happy to pay $8 per user for the Standard tier, or $12.50 per user for a Plus tier, or $48 per user for its forthcoming Enterprise tier.
It's a clever approach. The free tier is so good that some companies won't need anything more, but I'm betting that Slack feels it's infecting a generation of workers with the feeling that a workplace can't function without Slack--and that will gradually transform Slack into a must-to-have service for large organizations.
I've spent a lot of time writing about Slack, but I'd be remiss if I didn't mention a couple of other services that have colonized most of the groups I've worked with, owing to a solid set of free services. The first is Dropbox, which gives you a decent chunk of storage for free. Before you know it, people are sharing and syncing files and the service becomes a necessity. At which point, here comes Dropbox Pro (which I pay for) and, of course, Dropbox's more recent Dropbox for Business service. Dropbox finds itself in a field with a lot of tough competitors, but I started with Dropbox--and so I'm sticking with Dropbox. That's powerful.
Then there's Google, which has colonized countless workgroups with Gmail and the Google Apps suite of web apps. I've seen entire workgroups abandon their corporate mail system for Gmail, and abandon file servers and Microsoft Office for Google Docs and Google Spreadsheets. When I'm collaborating with someone on a document or spreadsheet, it's almost always via Google Apps. Microsoft has now gotten in the free web app (and iOS app) game, but Google was there first, and it has provided a powerful advantage.
What I'm saying is, the age-old technique of offering the first taste for free still works. If the product is good, it'll spread before you know it. And that's why you may have entire workgroups in your company using a free service without you even knowing it.