But it's less than 5% of what we do, PPC, Cold calling, and postcards still bring the bulk of leads. 

If you're looking off-market, join the fray with tons of other investors who are sending every owner on the public record their postcards, letters, phone calls, etc as Multifamily is very competitive in most markets here. 

I plan to hire a firm to do a direct marketing campaign to real estate investors - a series of 6 postcard mailings.2.

Also, an honest wholesale postcard would be this:"Will put your house under contract, but don't have any money of my own, so will then try to find someone else to buy the contract that I wrote with you (again, no money) and then I will take the gain in there for all of my very hard work of taking 5 photos and sending out an email and making up repair costs and ARV.

For example, you can pay people to drive for dollars for you, you can pay for services that send post cards to special lists, or you can set up a website where you can get leads and spend money on advertising your website.You are very correct on that competition is fierce right now!

Tons of postcards and letters which are ok but I hate these annoying phone calls asking if I want to sell.

I saw one of my friends in my list so I hand wrote on the post card "John, Pay your taxes you dead beat"  (not the real name by the way).

You will need at least a few thousand to your name to pay for the skip tracing, a few postcards, signs, software, gas etc.

I'm aware of driving for dollars method but it is time consuming.I suppose if their was a wholesaler who was already getting a good lead funnel through what ever means I would be very interested in learning about it and or potentially purchasing some of their contracts.Im planning on starting a mailing campaign soon and am also interested in finding a company who could handle my yellow letters/post cards if you have any suggestions! 

Thanks @Jonathan Greene - we've done a few postcard campaigns (nothing too personal) with company info and got our 2 biggest deals from this.