Thanks but here's where you're missing it... if presented correctly (later on, as a "special for my best clients"... but not right away.
Giving away a free session WILL net you another $300+ in orders from each of these families... they've already proven they'll spend that much on ONE kid... just think about the entire family.
So you give a free session and 1 8x10, they ask, "well can I buy other prints". You say, "well yes, of course, I'm not one to turn down money, but this offer was made simply to reward my best clients. If you like the prints, I'll be happy to take care of you, but there's no requirement or even expectation that you'd order any."
See you can get away with this because they already spent a ton!
My company is giving away a free 2-hour Engagement Session to brides that book a full photography (wedding day) package. They get an 11x14. I've already booked 3 of them and all 3 have asked (before the shooting, even) if they could buy more prints, and I say just about the same thing as I typed above. I can almost guarantee they'll end up buying the CD or $200+ in prints, which in either case we almost make up for the cost of the session to begin with (we charge $349 for 2 hours including 8 poses on CD with full printing rights, and an 11x14 print).
So they almost end up paying what they WOULD have paid... and we still book the wedding day photography
See, that's how you gotta think!
Interesting, I like the way you think! LOL I"ll have to try it next time. 
The school has 3 photo sessions (picture day) per year, 1 in the fall, 1 in spring, and 1 graduation. My next photo session is in the fall, the same school I just did has about 90 students, from what I was told by the principal this is the smallest school in their network! which mean I will be shooting 500+ kids from 5 schools without any assistant 
I will have to spread them out like 1 week per school, and I'm going to need help from my wife to sort out orders and proofs, and let her manage the payments. I have wasted way too much time in those silly stuff last time, I can only imagine it will be hell to do everything all by myself.
Ideally, I would prefer to provide low resolution proofs with watermark on CD, or have the parents check those proofs online. But I'm not sure if that would be too much of a hassle for the parents, I imagine some of them probably prefer to see the proof in prints....
