After having been through it as a parent, being "invited" to a school's camp is nothing noteworthy. The coach usually just wants butts in seats and dollars coming in. Granted, if there is a standout, he will get noticed...but camp interest is alot different than recruiting interest.
We did the Manning passing academy too, and for a 8th grader or freshman, it is pretty cool. For a rising junior or senior looking to get recruited, its a waste of time and money.