# Marketplaces NFTs created on the platform are fully compatible with the ERC-721 and ERC-1155 standards, which means they can be bought and sold on all Ethereum-compatible marketplaces, with Polygon/MATIC support coming soon! ### Earn Royalty Fees on Sales Buying, selling, and trading NFTs are a core reason why they are so popular. NFT technology enables true digital ownership, which means users can now easily buy and sell items that they receive from your app. As the [NFT Collection](/apis/mint-nfts/nft-collections.md) creator, you can easily **set a percentage-based royalty fee** that you will receive for all sales in compatible marketplaces such as [OpenSea](https://opensea.io). The default royalty fee is 2.5% of the sale price. You can change this while creating the [Collection Metadata](/metadata.md) or using our APIs. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.nftyverse.com/marketplaces.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.