After the FOAM Map launched, I found myself scouring the map to find points to challenge and challenges to vote on in response to the token incentives.

I started sending a daily email of new points and challenges (the FOAM Daily Digest, subscribe here) to help foster curation through discovery. Because you can’t challenge a point if you don’t know it exists.

This particular experiment in incentives has been especially compelling because maps are personal, political and change over time. This all leads to unexpected events that the community tries to make sense of. And along those lines, this analysis will try to make sense of how the incentives are performing.

FOAM’s Token Curated Registry

The FOAM Map is one of the first Token Curated Registries (TCRs) on the Ethereum mainnet. The concept of a TCR is to use tokens as an incentive mechanism for users to build and maintain a high quality list of information as a group. In FOAM’s case, a global map of useful and accurate places that can be used by dapp developers and end users.

Prior to the launch of the map, the effectiveness of TCRs was mostly considered through a series of thought exercises and blog posts. How will hypothetical users act with hypothetical incentives?

Now, we can look at how users are actually interacting with a TCR and start to draw conclusions about the effectiveness of the incentive mechanisms.

Mapping incentives

Maintaining a global map is difficult! This goal requires an ecosystem of different types of users. Those users and their incentives look like this:

Cartographers should add points that will not be voted off the map Challengers should challenge points that will be voted off the map Voters should vote on the winning outcome

The rules behind these incentives are:

New points require a stake (deposit). Any point can be challenged with a stake, which initiates a voting round. If the vote results in a point being invalidated, the Cartographer loses their stake and, in most cases, the point is removed. 60% of the stake goes to the Challenger and 40% is split between the Voters on the winning side. If the vote results in the point being validated, the Challenger loses their stake and the point stays on the map. 60% of the stake goes to the Cartographer and 40% is split between the Voters on the winning side.

Point Outcomes

The first way to determine whether or not the incentive structure is working is to see what is actually happening on the map. The following diagram shows the lifecycle of points on the map. Starting on the left and following the top line:

Cartographers added 7,756 points to the map

Challengers challenged 4% of those points

Voters voted to invalidate 93% of those points

FOAM Point Outcomes (Source: Blocklytics.org)

Cartographers and Challengers are doing a good job according to the incentives. Very few points are challenged. And the points that are challenged are almost always invalidated.

These figures are extreme from a game theory perspective. In theory, Challengers should try to take advantage of the 93% success rate and challenge points more frequently. However, for now egregious points are challenged and votes seem to happen in good faith. This is something to watch as the FOAM Map user base expands beyond token sale participants.

Speed of Challenges

Another way to measure performance of a TCR is speed. A healthy ecosystem is one where low quality points are quickly being challenged and removed from the map. The incentive structure gives the biggest opportunity to the Challenger that is first to find and challenge a point.

Challenger Speed on the FOAM Map (Source: Blocklytics.org

Nearly half of all challenges are initiated on points that are less than one week old. The long tail indicates that opportunities exist for Challengers to find and challenge points faster.

Cartographer Incentives

Cartographers are incentivized to add points that will not be challenged. So, why participate and risk tokens in the first place? This has been a contentious question in the FOAM community.

“The only winning move is not to play.” — WarGames (1983)

The strict structure of the token sale provides a great opportunity to peer into the motivations of Cartographers.

There is a reward for token sale participants to add their first 10 points (this unlocks their tokens and makes them transferable)

Beyond the 10 points and for non-purchasers, motivation is almost entirely intrinsic (users adding points for personal satisfaction)

FOAM New Map Points (Source: Blocklytics.org)

This chart helps see user motivations. So far 4,361 points contributed towards the token sale requirements and 3,395 points were added for other reasons.

This ratio is good news for FOAM. If the map was only growing because of the token sale requirements (blue area), the incentive structure would be a failure because there is a cap of 10,030 points that can be added for this purpose.

Intrinsic motivation is working (orange area). Points are being added to the map without a strong extrinsic incentive mechanism. (But in case you believe individual contributors consider their benefit to the platform before adding a point like their local coffee shop and, therefore, the token price and, therefore, themselves, adjust this conclusion appropriately).

Unfortunately, it’s not possible to definitely conclude whether the incentives are optimal. On one hand, a stronger incentive mechanism might result in more growth. And on the other, a stronger incentive mechanism may result in unnecessary spending for the same result.

Challenge Reasons

If you are thinking about adding points to the FOAM Map, you’ll want to avoid being challenged. The most common reason for a point to be challenged is an inaccurate location. For example, if a point describes a bridge but is located in the water next to the bridge.

The next most common reason is low quality metadata. For example, an incorrect phone number, typo in the title or missing tags. You can see the full list of challenge reasons here, along with how they are categorized for the graph below.

Try to keep these in mind as you add points and happy mapping!