This may help some of you guys, it may not, but I will try to give some insight and help.
What Brent Lykins mentioned on setting up an account with the small parcel guys is correct. Not only can you do that, but it gives you the ability to negotiate rates. Negotiation mainly comes in if you are doing some volume in your area. BUT always negotiate. These guys increase their price every single year by 5% or more. On top of this they change how pricing is calculated all the time..again mostly on an annual basis. They will negotiate. However, their price complexity is not decipherable(is that a word?) for anyone besides an NASA mathematician. There are entire businesses dedicated to taking your data, analyzing it, and filing for refunds with these two, all for a fee. They win a lot of it. On top of all this jargon, there are often rebates you can be owed on volume. This is the basics and not everyone qualifies etc. but anyone doing any volume with these two need to understand it.
3PL- That term has been used a lot in this thread. It simple means 3rd Party Logistics. This is a freight broker, plain an simple. A middle man. They have contracts with LTL carriers and ship freight. Most do not own a single truck. They get a cut of the money for brokering the freight. The water gets muddy here in that some LTL companies also have a 3PL division. XPO is one of these. Not only are they one of the largest LTL carriers, they also operate as one of the largest 3PL carriers. Meaning, they can send shipments via their own trucks OR they can farm out the shipment to a competitor such as ESTES etc. I do not like 3PL in that it adds an additional party to the equation. However, it is the way of the world today and it can offer a savings. There are national LTL carriers such as ESTES, ABF, XPO, OLD DOMINION, FED EX FREIGHT, etc. also regional like AVERITT and SOUTH EASTERN FREIGHT. You can set up accounts with these people too. And like small parcel there are about a 100 or more hidden charges you can get nailed with. BUT these would take a 3rd person out of the equation, negotiate discounts, and you can do volume quotes. If they need freight into an area you can get a volume quote (depending on size and weight) and potentially save a lot of $. Be careful though since they can get delayed depending on carrier.
I recommend contacting an LTL carrier and discussing your needs with the local rep. On top of that, get quotes. This is the best way to stem off surprises and save money on anything not going small parcel.
Anyway, welcome to the world of shipping. This is just the tip of the iceberg. I should write a book on the subject, it is a racquet. Freight is a complex nightmare for those who have not waded in the water. The days of a fair price and easy process are gone in this arena. I may be a little jaded since I deal with it daily.