I don't worry about building rapport with tire kickers, no. So many people call to actually bust chops or yell at you for sending them a letter that to me at least, its just not worth it. The leads are not completely qualified but if the person is really interested in selling he or she will leave her info. No matter how you decide to do things, its still a numbers game.
Hiring a call center is on the expensive side but my time and stress is worth hiring them. Im not dealing with ticked off people all day - they are and to me that's a huge bonus in itself.
I am honestly still getting started. I've done a few small mailers and have had several leads come through but I am literally dropping off my first partial batch of 3000 this morning. For now, Im dropping off about 400 mailers every 2 or 3 days for the first 3000. Im shooting for 6000 pieces per month out the door but am finding it is waayyyyy too time consuming to do myself at this volume, even with a proper printer. Just stuffing all those envelopes is taking me and my kids forever.
@Michael Q. saved my butt on this mailer by sending me a new batch of Yellow Letters free of charge after I messed up my first batch of 3000 (I put the owner's mailing address where the property address is supposed to go on all 3000 original letters).
As for the costs - I think it works out to $100 a month plus about a buck a call which is expensive but again, worth it to me. I also rent a vanity 800 number from them as well. Their rates are posted on their site.
The nice thing about the call center is they will pull whatever script you send them depending on who is calling so I can build my investor list too and they call the same number but get the "investor script" which asks for their contact info and some investing preference info.
I have another business outside of real estate from which I learned early to automate as much as I possibly can so I can concentrate on the really important stuff. I just don't have the time or blood pressure to support dealing with all those initial calls. If I lose some, I lose some but the call center guys are trained to handle these type of leads. They know what they are doing.