Maybe they need to get to know you . Sometimes you have to build the relationship first.

I am a home inspector, so I come at this from a slightly different angle.  I have had the same difficulty.  I have found that the biggest problem is deciphering which agents are serious about their work and which ones are part time.  I haven't found a good answer for me or you.  I just keep weeding through to find the professional agents.  Hope this made sense, it does in my head at least.

I want to add my two cents worth....I have one lender I work with because I know that when he has a client I can help he sends them my way. More importantly I know he will take the best possible care of the referral.

In past experiences I have sent leads to lenders who want to "work" with me and my clients/customers only to have them try to send them to other agents. This makes my gunshy when dealing with lenders.

I do think that it takes time to build relationships with people first.  Many people in the real estate industry, especially here in the Atlanta area, are slow to partner with people that they don't know.  Just keep building your presence here on active rain and keep your in person networking going.  Eventually you will build a network of realtors that will refer work out to you.  Just my two cents.