Reality check.
The fact is there are very few that operate as a sole independent with their own customer(s)
Can only wear so many hats in a day.
They are there and it can be done, but it is hard work and it would be a difficult choice to put all your eggs in one basket.
As pallet jack mentioned, the differential in rates isn't high enough to offset the difference on a continual basis unless you have a real knack for locating freight from unconventional sources. There use to be a lot even 5 years ago, but reality shows much different in today's time. Seldom do you see someone operating this way past the five year mark. There are exceptions, but pretty few. In fact, I can't think of any at the moment that are currently running.
The real reality is the independents are very reliant on the folks "in the glass towers".
A lot of companies prefer a logistic company because they want guarantees, one stop shop, and assurance that any freight they have can be covered. One single independent can't offer that.
To get close they may try GPS but that is a lot of LTL, NLM and a shark frenzy when there is little freight.
Most of these "independents" are getting their freight from Panther, Fedex, Landstar and so forth. The rest are using 3PL's or load boards. Just to stay diversified, we do a little of all of them.The more sources for freight with cost containment, the better.
Just want to make sure the person going down this path has a clear idea of what they are jumping into.