# This could be your ad!

Source: https://github.com/attestate/ad?tab=readme-ov-file#how-does-it-work
Kiwi News: https://news.kiwistand.com/stories/This-could-be-your-ad?index=0x66a8d1b528692b74d2cc26f3bd3dfc3bcd6c874a0fc09f9afe4fa6340a93a1c268e86b04
Submitted by tim on 2024-07-30 UTC, 4 upvotes, 0 comments

## Summary

Kiwi News offers ad slots on its site through a smart contract that uses a Harberger-style pricing model, where the ad's price is set by collateral staked in ETH. The article says the site reaches roughly 150 to 400 individuals in the crypto space a day, and the contract is meant to help discover what that audience is worth to advertisers. The owner pays a fee equal to 100% of their collateral per month, and the staked collateral doubles as the price another buyer must pay to acquire the ad. An update dated 2025-04-21 notes that the ad was removed because the website did not have enough impressions to be a good business model at that time.

## Article

Update 2025-04-21: Removed the ad from Kiwi News. The website didn't have enough impressions for this to become a good business model for us at that time.

How does it work?

This contract will give you access to set an ad on https://kiwinews.xyz. The ad will be, for example, permanently available as the top fourth link here:

At the time of writing, we reach roughly 150-400 individuals in the crypto space a day. But we have no idea how much it'd be worth to advertise to these people, hence the smart contract. It'll help us do price discovery. So how does it work?

Basically, you can stake an amount of ETH for the contract to be yours. Say you stake 1 ETH, then you'll get to set the title, link, and you'll own the contract. But over 1 month, we'll charge you 1 ETH in fees (100% of the collateral a month). The ETH staked as collateral in the contract is also the price someone has to pay to acquire the ad from you. Here's an example:

Day 0: You stake 1 ETH in collateral. The price to transfer the ad is 1 ETH.

Day 15 (half a month): Now half of your collateral was taxed (0.5 ETH). The price to transfer the ad is 0.5 ETH. Your remaining collateral is 0.5 ETH.

Day 30 (month): Your ad is about to be taken off the website. In case noone has bought yet, your collateral now is very low 0.0000...1 ETH, and so for someone else to buy the ad space from you is extremely cheap.

Now, what would happen if someone bought your ad for 0.9 ETH on Day 12? The new flow would be:

You deposit 1 ETH on Kiwi as collateral

On day 12, there are 0.6 ETH left (the rest, 0.4 ETH, is locked for taxes)

Alice wants to buy the new ad for 0.9 ETH. What happens then:

0.6 ETH from Alice are sent to you

0.3 ETH from Alice are kept as collateral for the new ad

0.4 ETH from your old collateral are sent to Kiwi for the taxes

0.6 ETH from your old collateral are sent back to you

Now:

You have 1.2 ETH (0.6 ETH leftover collateral + 0.6 ETH from Alice)

Alice has 0.3 ETH as collateral on Kiwi

Kiwi has 0.4 ETH paid from taxes from your ad

You may have heard of this concept earlier. It's often referred to as Harberger taxes, or Partial common ownership. Check out this talk from Devcon SEA about "Demand-based recurring fees in practice" to learn more.

How to buy the ad?

Go to https://news.kiwistand.com/submit and check "Submit as an ad."

Deployment

CREATE2 is used to deploy the contract to a deterministic address independent of chainId.

DEPLOYER: 0x0000000000ffe8b47b3e2130213b802212439497

SALT: 0x0000000000000000000000000000000000000000f00df00df00df00df00df00d

INITCODE: 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

ADDRESS: 0xffcc6b6c5c066b23992758a4fc408f09d6cc4eda

Deployed to:

Optimism

Updates and verifying on Etherscan

ETHERSCAN_API_KEY=abc forge verify-contract address Ad --watch --chain 10

License

SPDX-License-Identifier: AGPL-3.0