If you want to make your NFT marketplace popular, you should adopt some admiring features that bring great attention.
Appealing Storefront
Bidding Strategy
Security Features
Wallets Integration
Token Search
Token Listing
Token Rating
For More: newbie deactivated link:https://steemit.com/nft/@katrinkunze/a-guide-on-how-to-develop-an-nft-marketplace-platform [nonactive]