Viral marketing

Users bringing users, because the product makes something worth passing on.

What it is

One of the 19 traction channels. S3 Skok defines the viral coefficient K as invitations sent times conversion rate, and K must exceed one for viral growth. S8 The virality lane fits when the product gets better with network effects among friends or colleagues, or is inherently shareable. S6

When it works

When sharing is load-bearing in the product, not a button added later. S4 Skok’s finding is that cycle time matters more than the coefficient: over twenty days at constant K, a two-day cycle produced 20,470 users and a one-day cycle over twenty million. S8 Bodnick’s critique is that if the initial product does not include integrated social functionality, you probably will not build a strong network later. S11 Janz’s tiers say virality is arithmetically irrelevant at high prices and necessary at very low ones. S5

What it needs from the product

A public artifact: something a non-user can see, such as a profile, a shared page, an embed. And a customer count large enough that a loop is worth building. At a few dozen customers you have a sales problem, not a loops problem.

How it decays

Chen finds viral loops and referral among the degraded mature channels. S25 The three-lanes benchmark is more than half of new customers arriving through word of mouth; below that, the loop is not carrying the business. S6

What the report checks

The arithmetic gate needs at least sixty customers in your target. The structure gate needs a clear public profile or share pattern in your sitemap. That pattern cannot be inferred from the outside for most sites, so this channel often lands in Could not check, which is honest rather than a verdict.

Viral marketing

What it is

When it works

What it needs from the product

How it decays

What the report checks

Sources