You may already have chickens and considered including guinea fowl to your farm. Although some may think they are similar, I can tell you, they are different in many ways.
Before I bought our young guinea fowl, I did some research and was told, that you would always be able to sell the chicks. This was true, in fact I sold them for more than I thought I would. That is one thing in their favor.
They also eat ticks which is a bonus because we get a lot here, especially if it has been a particularly wet season.
They also scratch less than chickens which is good as chickens, can be so destructive.
Our guinea fowl are free range and they cover vast distances so it is best to only get them if you have a good relationship with your neighbors as the birds don't understand what a fence is for.
Although we have barbed wire close together, and mesh on other parts, they get through or over it.
They also are noisy. Extremely noisy. I have read that this is good because it could be used as a security system. This is not true because if you remember the story of the boy who cried wolf, it is like that. Guinea fowl will scream, if a plastic bag is floating around, if a hoe is in a different area than normal and sometimes they just scream for no reason. This of course makes you switch off to a “danger call”.
To be honest with you, I don't know how this breed of bird isn't extinct in the wild. They alert all animals around to their presence with their constant chattering and they are some of the dumbest animals I have ever met.
That said, they are entertaining.
Guinea fowl have a communal nest (usually hidden) and to be honest with you, are awful at nest management. If you have a broody hen, you are best to remove some of the eggs and put them under her. Or consider buying an incubator. The guinea fowl eggshells are hard, in fact to crack them, I have to hit them on a corner. How those chicks get through is amazing.
The chicks are much more fragile than baby chickens. The legs are weaker and can splay out. This can be corrected but it is time consuming. We have tried it as instructions are available on the internet but in the end we had to put the chick out of his misery as we never thought it would walk correctly.
Besides selling chicks you can also sell the adult birds as meat. These will command a higher price than chicken.
Also consider selling the feathers. They are beautiful and used in crafts. Places such as Ebay are ideal to sell them. Or consider making products and selling them on ETSY or at craft fairs.