Like him or not, Alan Jones' 'Bacon and Egg' principle has merit: the chicken 'attends' while the bacon is committed. As a broker, you're either the chicken or the egg.
With all we know about the non-compliant and dodgy ways scrappy leads are garnished via those that sell them, brokers keep buying them, despite the fact you can easily introduce systems into your own business that are infinitely more powerful and profitable (and we're taking about solutions that multiply your ROI by 100X when compared against crappy 'leads').
Those that generate their own leads have a business; those that buy them are processers for a leadgen company.
There's a reason that the tech and narcotic industries both survive on 'users'... and we'd argue it has less to do with addiction and more to do with the nefarious supply chain.
Buying leads does *not* scale a business.