Turning your written content and making money off it was going on in many blockchains. And there seems to be growing demand for the images being turned into the NFT. You can use the DeSo blockchain's coins for earning out of the marketplace. So you create the NFT and then you sell them in this marketplace. And this balance of earning would be available in your DeSo blockchain wallet immediately. You also earn the royalty or one time sell out of the NFT of the blockchain.

Here's one of such NFT store I created. For every NFT uploaded on the marketplace some initial fee is being taken. And also the income would be capped with the royalty rate and the platform price. 

You can check my store and NFT here. This would allow you to check either one time price or the bid. Bid systems are good if you want to earn higher. You should definitely keep the NFT for the higher bid. Small bids would easily sell your NFT without you having to do anything as such. So make sure to experiment with your own content and see what sells and works like bid or one time.

Who should use the NFTz and the DeSo marketplace on the diamond, focus and others?

You can be a good content creator like say artist, cartoonist and other authors who want to design the content and that can be turned into an NFT. I think if you have subscription to the tools like say Nigthcafe studio and the Leonardo AI. So once you start creating an digital asset using the AI you can turn them into NFT. Make sure to pay for the account like those so that you can have the ownership of the assets that you create. Like it may even earn you good if you hold it and create the NFTs. So try some of such tools and subscribe to them for like year or so. 

DeSo is a good blockchain, it can be used to sell stuff. How much you can make out of it? Nobody knows. But it can be a good option for income. Though you should not expect much unless your NFTs don't have a utility. So gamers, bloggers and others with lack of utility would find it not so easy to sell. 

You can check out the NFTz.