Double-sided Incentive

The first version of any invite reward usually pays only the referrer. You are paying for the behavior that brings someone in, the design is easy to explain, and it costs half as much.

The catch is that collecting that reward requires talking to a friend. Once the act looks like sending someone a link so that you can collect $4, most people don't send it. Raising the amount makes it worse, not better, because a bigger number makes the favor more obvious.

That's roughly what happened when Ravi first put an invite button in Pagedeck. One free month went to the inviter, the button ran for a month, and forty invitations came back — a dozen or so of them from second accounts belonging to the same person. Asked why they hadn't sent more, the people who did invite real colleagues gave similar answers. Sending a link that paid them felt awkward.

A double-sided incentive is built to remove that awkwardness. Pay the receiving side too and the identical link stops being a request for help and becomes something you hand to someone. Even the sentence attached to it changes: "do me a favor" turns into "you get a free month as well."

The whole design is deciding what each side gets and when. There are four decisions.

1. What to give. Cash-like discounts sit on one side, in-product rewards on the other. Cash moves fast but attracts people who collect the reward and leave; storage, unlocked features, or extra seats move slower and bring people who stay.
2. When to give it. Paying the moment someone signs up produces invitations that end in an empty account. Paying after the invited team has created its first document produces fewer invitations and a higher share of people who stick. Pagedeck picked the second: one free month of the paid plan to each side once the invited team creates a document.
3. How much in total. Cap what a single account can accumulate. Without a cap, somebody will open twenty accounts. Pagedeck stops at three free months per account per year.
4. How to verify. Matching payment methods, matching devices, and personal rather than company email addresses are the usual signals for filtering fake invitations.

The cost isn't "double." It's two shares per successful invitation. At $15 a month for the Pagedeck paid plan, one invitation costs $30. Put that number next to customer acquisition cost (CAC) rather than next to the one-sided version. If paid advertising brings in a team for $70, a $30 invitation is the cheap channel; if advertising is already delivering teams at $25, there's no reason to attach a reward at all.

The effect gets measured with the viral coefficient, the average number of new users one existing user brings in — 100 teams bringing 30 teams is 0.3. If switching the reward to both sides moved that figure from 0.1 to 0.25, the number of users advertising has to cover dropped by the difference.

Before attaching any reward, check whether the product is something people have a reason to spread. It works best where there is a network effect — where each additional user makes the product more valuable to everyone already in it. A collaborative document tool qualifies. Your teammates have to be inside before you can review a document together, so inviting them pays you directly.

Subscription products are a good fit for a second reason. The reward is time on your own service, so what actually leaves the company is far less than the sticker price. You give away a $15 month and spend a few dollars of infrastructure on it. In a business that sells a physical item once, the same reward is cash out the door, and the design gets much harder to justify.

Where a product is just as useful alone, the whole mechanism weakens. A friend using the same budgeting app doesn't improve your records, so the reward is real and the reason to invite isn't. Attach a double-sided incentive there and you collect people who came for the reward and leave together when the first month ends.

Choosing the reward also doesn't finish the job. The same offer produces results several times apart depending on the invite flow around it. An invite button buried in settings yields 40 invitations a month; the same offer surfaced at the top of the screen to someone working alone in a document yields 400. The intent is identical — the distance to the button is not.

"Our invite reward is one-sided. Let's pay both ends, because right now senders feel awkward."

The problem is the shape of the ask, not the size of the reward.

"I moved the payout from signup to first document created."

Fewer invitations, a higher share of people who stay.

"A month to each side is $30 per invitation, and advertising is running at $70."

The reward is cheaper than the alternative channel, so it's worth attaching.

At Pagedeck, Ravi is usually the one who opens this discussion. In quarterly planning he puts two proposals side by side — raise the advertising budget, or rework the invite reward — and writes the cost per acquired team for both in the same table. Sofia adds a line to it: track whether teams that arrived through the reward are still around three months later.

Without both numbers the decision flips often. On cost per acquisition the reward wins almost every time, but if reward-driven teams retain at half the rate of advertising-driven ones, the reward is the more expensive channel after all.

The most common assumption is that raising the reward raises referrals proportionally. More money should move more people, which is a reasonable starting guess. Amount and volume don't track each other. Going from $4 to $8 changes nothing if the act of sending still feels awkward, and a larger number tends to attract fake accounts before it attracts real ones. Double the payout, see invitations rise 30 percent, and find half of the new ones fraudulent, and you have doubled spend while real users went down.

The second is reading the two-sided payout as a loss because it costs twice as much. Against the one-sided version the per-invitation spend is exactly double, so the reading is understandable. The comparison is aimed at the wrong thing. A reward competes with whatever else would have acquired that customer, not with a cheaper version of itself. Acquiring for $30 what advertising delivers at $70 cuts the cost by more than half. Teams that see only the doubling and revert to one side watch volume fall back to where it started, and the users lost outweigh the money saved.