So I called the verizon "go digital" number, and had this conversation:
me: "I'd like to get my free set top boxes"
[account verification dance]
csr: "I see you already have have set top boxes, so you don't need any boxes"
me: "right, but I have to pay for those"
csr: "yes sir, we are just giving free boxes to those that don't already have them"
me: "so... if I didn't have them, I'd get them for free, but since I have them already I have to pay for them?"
csr: "that's right sir"
me: "that doesn't sound fair does it?"
... maybe I'll call back and tell them I have 6 Tv's and only 3 set top boxes - then when I get my 3 free ones, I'll give the 3 pay ones back...