Well at the risk of eventually outing myself here, I've started to follow the college recruiting scene a little more heavily due to having a son that wants to play college football. What I've discovered so far, at least if you are from the state of Iowa, is that it's pretty difficult to make P5 schools notice you, unless you're dedicated to non-stop football camps (Nike, UA, etc). My son is not doing that; he is a 4 sport kid; Football, basketball, baseball, track. He has no time for any camps. In fact, most HS sports want you training year-round for their sport, which is impossible if you play multiple sports. The only thing my son is doing year-round is lifting weights, and even then it's spotty. Right now, it's obviously track season. My son is a hurdler, and he's got a hip that has been problematic since last track season. He ended up qualifying for state last year on the shuttle hurdle team, but couldn't end up running due to the hip. Then, during football season, he missed another game due to the same hip. Now it has been acting up a bit in track the past few weeks, so he's taking a few weeks off from weightlifting. Baseball guys have been hitting and throwing since January; my son hasn't gone once. He was in basketball, then immediately shifted to track. Basketball season ended, but now they have open gym a couple times a week. Again, he hasn't gone once, even though the coaches want him there (track coaches DO NOT want him there; we had a track kid tear his ACL/meniscus last weekend at basketball).
My point is, if you play multiple sports in HS in Iowa (probably most states), it's really hard to focus on being recruited in any particular sport, unless you stand out physically, then you sort of recruit yourself. The rest of it appears to a compilation of your work over time, coupled with impressing someone at a camp, if you get the opportunity to go.
My son is just finishing his sophomore year, he's young for his grade (16 at the end of July), but presumably just based on hudl film (I don't really know, but it's the only thing that seems reasonable), he has a ton of camp invites from D3 schools this summer. He doesn't have a single sniff from a D2 or D1. That being said, He's doing a D3 camp, and then he's going to Iowa and Iowa State camps. He knows that he has to impress the heck out of someone at either of those camps, otherwise that will likely be the end of his D1 opportunities.
One of the other comments about productivity is also interesting, I guess especially for a receiver like Andregg. I think it's a lot more difficult to put up numbers as a receiver in Iowa, for a number of reasons. There aren't a ton of offenses geared towards throwing in Iowa (colder, windier), and then it depends on the team you play for, how much talent they have, and their philosophy on offense. I know where my son plays, we rarely throw the ball, and we rely on 4-5 running backs throughout the game, so it's hard to showcase an athlete. Further, at some of the 4A schools in Iowa, the talent pool runs a bit deeper, simply because the schools are larger, more kids etc. If you play at a smaller school and are good, your chances of playing varsity at the freshman or sophomore level are much greater than at one of the better 4A schools. Then, if that 4A school is a decent team, they typically will have multiple guys on offense, so producing big numbers as a receiver is pretty difficult.
Anyway, sorry for the rambling post, just thought I'd lend a few thoughts based on my very early experiences with trying to help my son find the right fit for college.