You mentioned this already mamoore but I wanted to expand on it.
BUILDING RELATIONSHIPS WITHIN THE MORTGAGE INDUSTRY (ie. realtors)
This will always be your best source of business. The question is how do you get in door of some of these realtors. Most realtors have been working with the same LOs and Brokers for years. How do you build that realtionship and get referral business for years to come? Bring the business to the realtor. Its simple, you contact renters with a certain monthly income and have a good rental history. Get them prequalified for a loan. Call up the realtor you would like to start a relationship with and tell them you have a client that needs a house. You already have them approved for a certain loan amount so the realtor knows exactly price range the client is in and hopefully finds them a house ASAP (so you can get the loan done and get paid

). You have now started a profitable relationship with the realtor. Send a few more preapproved purchase deals their way and you got a lasting relationship with that realtor and in turn hopefully get their referral business as well.
If you are interested in purchase leads in any state call me at 602-200-8280.