It's all about leads, leads, leads, isn't it? Whether you're a new freight broker starting out, or have an established book of business you can never have too many leads.
One of the best resources we've found outside of LinkedIn is the Industrial Quick Search Directory (IQS).
The IQS compiles and links to all the different industrial and manufacturing associations in North America. This includes associations for companies manufacturing, conveyors, fabricated steel, auto parts, heating units, pumps, etc., etc., etc.
And of course our favorite email hunting tool at CarrierLists is Hunter. The stalking tool to find anyone's business email address. Everyone here at CarrierLists uses it on a daily basis, and has the chrome extension installed for quick access. You should too.
P.S. - Final edits on our 10K edition are now being made. An expected late August launch date will give you access to 10,000 carriers with over 450K tractors. We'll keep you posted with more details...