There have been examples of companies that grew without a sales team. Dropbox in the beginning was growing via network effect and their gimmick of get more free space by referring a friend. Boom! That gimmick was a Growth Hack tactic. Then sales had to come in and start upselling the freebies to paid accounts.
Slack has had incredible growth in just two years - 2 million daily users and it will be 3 million before year 3 is up. How did they grow? Well, the CEO explains that here. In short, he says if you make an incredible product, you won't need sales. Word of mouth will be all you need.
Unfortunately not enough thinking and, later on, improvement goes into product design. The improvement is just features or playing catch-up to the marketplace. More companies should leverage the Lean feedback cycle.
"If the company had an amazing product, and an amazing brand, they wouldn’t need to be hiring for that sales role in the first place." (or so the story goes. Still need some marketing.)
"We do know that during the first several years, Slack didn’t have an outbound sales team, nor did they have an elaborate marketing operation. So cold-calling and lead generation/lead nurturing campaigns, the staples of many high-growth SaaS operations, weren’t levers they were pulling. And yet, Slack was able to go from 0 to nearly $4 billion in less than four years." Read the article.
I have said many times, if the Customer Experience (CX or UX) was improved - the deployment, the install, the follow up - much like Zappos and Mindspring - you could grow with less salespeople, and do it with just a little marketing*. (*Although marketing IS improving the CX.)
Look at Google Fiber: Google focused on pretty (office, packaging) and unique (Gigabit Fiberhood) and different (CPE and No Voice originally), and the hype went through the roof. It only resulted in less than 150K subscribers*! I detailed much of that in Marketing Your Fiber (you can get the slides and mp3 here).
* Much like Covad and the other DLECs who didn't comprehend how the ILECs would make it hard on you; Google didn't fathom how hard regulations, status quo, power companies, the Duopoly and fiber construction would be. Huge hurdles to overcome - again and again.
20 Slack Apps You’ll Love (integrations with Slack) by ProductHunt.