Camps are for two main purposes.
1. To make money for volunteer assistants and/or to fund something for the program. The money from camps goes to the assistant coaches normally. That is why they are the ones who run it and responsible for everything. Many times the HC or RC is not even present which is wrong in my opinion. You would think that if you are going to a camp at X college/university the HC would always be present but that is not the case.
2. To have contact with true prospects. They will invite guys to come to campus and get to spend time with them legally. At a camp, they can interact with them legally.
2A. To find prospects. This is a side product of camps but very rarely happens. People who are not in the know think this is where you get seen.
3. To teach the game. This very rarely happens unless it is a specific camp like pitcher/catcher or hitting. Most of the camps are for making money and interacting with recruits.
The schools pay a lot of money to have very specific recruiting email lists especially for camps. They have great programs that word the emails like they are specifically for each player. The better they can do that the more money they make. It is hard to tell. Many are also realizing that if they send it from the HC or RC's email address which is normally public they get better responses. If it is legit from HC then he will normally put something specific to your kid like I saw you play at WWBA against the Titans. Would love to have you on campus at our camp XXX and be able to see you in a controlled setting.