List size for 1-2 deals per month?

[Steve R.]

Interested in hearing opinions from people who are actually consistently closing 1-2 or more deals per month.  

I bought a list of 400+ and sent out around 200 letters, and got 12 calls.  Most of which were tire kickers, but I looked at one house.  Overall there was no deal, my friend who does many flips per year came with me to look at the house and help negotiate.  The guidance is nice, since I am new to this.  Good learning experience, regardless.  That said...

I am going to diversify my mailing groups, but overall how many postcards/YL would you send if you wanted 1-2 deals per month?  Would 1000 mailers per month be sufficient to various prospects?