Would be free advertising and networking for wholesalers and would help move deals faster.  

I recommend setting up keyword alerts for each area as they are discussed in the forums daily with advertisements posted in the BiggerPockets marketplace hourly.One thing to note when looking at the individual markets, you can make or lose money in any market.

My goal is to generate deals, wholesale the ones that don't fit my needs and cherry pick properties.Mailers are relatively inexpensive (4k or so for an aggressive campaign) but are they effective?

Is there a website where you can advertise your property for section 8 tenants?

Private Lenders do not advertise.  

(And as you already know, I am right.. you are doing this for a year already without luck).So now you will send  1 person 7 mailing campaigns... now based on what do you decide to do this?

Most listings over 10 units are typically marketed by a single brokerage who may or may not advertise it on their website.

So far, most of the work was in the advertising, and tenant selection process.

Cozy can also be used to advertise the property, which syndicates the ad to multiple other public real estate websites. 

Many multi-family properties are advertised with the income, but they don't tell you the expenses.$1,300 is a ridiculous amount for a duplex.