No mortgage broker leads, just one wholesaler (a good one - but be careful, there are tons of shitty ones!) and just contractor connections, telling people that I'm a cash buyer and look for X homes in X area...people, in the right markets, will accept a discounted sale price for quick and painless closings, not dealing with financing, agents and all the bullshit involved with a traditional sale.
I should note that my market is not a super hot one, although things are picking-up. People probably care less about cash buyers in SoCal vs Northern Ohio, where I buy.