I agree. If you're doing mostly subcontracting work and that's what you want to do, it becomes almost entirely a matter of knowing the right people at the right companies, and networking is the way to go there.
If there are any key vendors or suppliers in your marketspace, getting close to them can be helpful too. My current employer recently started partnering more closely with Microsoft, and the local MS staff was fairly suprised to find out about us. Even though we were the largest consulting firm in town, the fact that we were a local firm kept us below their radar. Now they're throwing all sorts of business our way.