Ocean Protocol offers 3 types of pricing options for asset monetization. The publisher can choose a pricing model which best suits their needs while publishing an asset. The pricing model selected cannot be changed once the asset is published.
The price of an asset is determined by the number of Ocean tokens a buyer must pay to get the access to the asset. When users pay the right amount of Ocean tokens, they get a _datatoken_ in their wallets which is a tokenised representation of the access right stored on the blockchain. To read more about datatoken and data NFT click [here](/concepts/datanft-and-datatoken).
With the fixed price model, publishers set the price for the data in OCEAN. Ocean Market creates a datatoken in the background with a value equal to the dataset price in OCEAN so that buyers do not have to know about the datatoken. Buyers pay the amount specified in OCEAN for access. The publisher can update the price of the dataset later anytime.
A [FixedRateExchange](https://github.com/oceanprotocol/contracts/blob/v4main/contracts/pools/fixedRate/FixedRateExchange.sol) smart contract stores the information about the price of the assets published using this model.
Publishers can choose this fixed pricing model when they do not want Automated Market Maker(AMM) pools to decide the price discovery. If the publisher has already analyzed and estimated the worth of the dataset and is ready to sell an asset at a constant price, this is the suitable pricing model.
With dynamic pricing model, he market defines the price with a mechanism derived from Decentralized Finance (DeFi): liquidity pools. While the publisher sets a base price for the token in OCEAN, the market will organically discover the right price for the data. This can be extremely handy when the value of the data is not known.
The publisher creates an Automated Market Maker(AMM) pool of Datatoken and Ocean tokens in dynamic pricing. *AMM* enables unstoppable, decentralized trading of assets in the liquidity pool.
A *liquidity pool* is a reserve of tokens locked in the smart contract for market making. A buyer or a seller of an asset exchanges token **x** for token **y** or vice versa. AMM calculates the exchange ratio between the tokens based on the mathematical formula above.
Ocean Protocol facilitates the creation of Datatoken/OCEAN liquidity pool with [Balancer smart contracts](https://github.com/oceanprotocol/contracts/tree/v4main/contracts/pools/balancer).
While publishing an asset with dynamic pricing, the publisher decides the initial ratio of Datatokens and Ocean tokens in the pool, thus setting the initial price of an asset. The price of an asset is later dependent on the pool's liquidity and the price impact of trade in the pool.
Publishers can set the pricing model of an asset to Dynamic pricing if they want the market to decide the asset price and thus enable auto price discovery.
The image below shows how to set the Dynamic pricing of an asset in the Ocean's Marketplace. Here, the asset price is initially set to 50 Ocean tokens.
With this pricing model, datatokens are allocated to the [dispenser](https://github.com/oceanprotocol/contracts/blob/v4main/contracts/pools/dispenser/Dispenser.sol) smart contract which dispenses data tokens to users for free whenever they are accessing an asset.
Free pricing is suitable for individuals and organizations working in the public domain and want their datasets to be freely available. Publishers can also choose this model if they publish assets with licenses that require them to make them freely available.
