“Are We Viral?”

a brief history of growth at Yammer

Initially an answer on Quora, here’s a quick tour of Yammer’s viral features and how they evolved over time.

DISCLAIMER: These are strictly the viral features of Yammer. The vast majority of Yammer PM/Engineering time is spent making the product engaging. The engaging product, more than any viral feature, has always been the real secret to Yammer’s growth.

Yammer initially spun out of Geni, a genealogical site that sought to group all of humanity into one big family tree. That family tree was the core functionality of Geni as well as its’ viral element. When you added relatives’ emails in the tree, Geni would invite them to participate.

From the beginning, the same tree was part of the Yammer sign-up flow, but now as the company org chart.

It would similarly invite people in your company.

The early team also added a simple in-product invite link and page.

That link went to a dialog like this.

Later this dialog replaced the Org Chart in the signup flow. I’ve always found it a little baffling that this dialog was effective, as we hadn’t given the user a good understanding of the product or why it was valuable yet. The dialog also requires a lot of manual text entry.

But, try as we might to improve this experience, it persists to this day in largely the same form.

Here you see one evolution including the org chart and the invite link.

Later iterations of that invite page included address book import as well.

This was always a little weird for us though. Though we iterated on this dialog, we knew most of our users were using Outlook/Exchange, so the value of this feature was limited.

With this iteration, now a few things changed:

• Communities — now Yammer could be used between companies with different domains. These cross-network-effects aren’t super strong for Yammer, but they do come into play.

A model of Yammer cross-network-effects in pharma circa 2012

• An invite box on the main page, partially replacing some of the need for the multiple text box page. Leaving us free to experiment with…
• A more flexible invite dialog. Now linked from the old invite page and the people pages.

Yes, that green button is a little close to what Nir Eyal would call “viral oops”. But it is important to note that it only re-invites people who have been added already, either via invite or users uploading their phone contacts.

Another iteration of the landing page:

Invite is now over to the left. Inviting is also suggested as part of the “Getting Started” checkbox. Suggested People is a seed for something that would come later.

We’re pretty close to the modern incarnation of Yammer here:

Add opens that search/invite dialog from above and we’ve added a couple elements that are now closer to real viral loops:

1. Users who have been invited can be at-mentioned like confirmed users and you can also at-mention them via their email address. Their new “invite” email contains a copy of the message, so they know a bit more about what they’re doing.
2. That Suggested People dialog now includes users who have been invited, but not confirmed. The subsequent invite email informs them that the user is interested in what they have to say in Yammer.

There are countless other little features used to draw in new users, but that’s a survey of the most successful. It is worth noting that k-factor is not the end of the story.

Some of the most successful features for sending out invites lead to our lowest quality users:

As we discovered, acquisition source affected long term engagement (DAU & MAU):

And, really interestingly, acquisition source affected the k-factor of new users:

There’s five years of growth tactics and some of what we learned. I’m sure the team is applying this knowledge and iterating on these features today (if not trying something more radical).