I’m just going to dive in with no preamble, so here goes.

A company’s organization and culture is often a function of it’s size. Here’s what I’ve learned working in companies of various sizes:

1-2 People. Single-Owner or Partnership.
Because one or two people are the only people, they have to do everything. Smart companies figure out how to carve out a little time to outsource the things they aren’t good at (billing, marketing, etc), though most companies wear the “I’m too busy working to think about how to work better” badge like a medal and don’t grow as fasts they want. Usually, this leads to burnout.

3-7 People. Personal Business, Mom and Pop Shops and Hobby Businesses all fit into this group. This is an extension of the previous group in that the owner(s) still do everything, but now they have a little help with the things they hate doing or the things that are most profitable. Owner can take an occasional vacation, but really, they are just a bigger version of the single-owner. Burnout a real issue, as is employee morale: unless you’re a family member, you’re probably an hourly employee and you’ll be lucky to see a raise or benefits.

8-40 People. Small Business.
The company has turned a corner and figured out how to “go pro.” The employees are salaried with benefits or are contractors. The owner will still work had, but now they’ve built a platform on which they can rely more. Will take annual vacations, maybe even hold company picnics and Christmas parties. The company os almost completely flat – the owner has direct knowledge of every price of business going on every day and everyone reports to the owner. The owner has figured out how to delegate tasks, but not necessarily responsibility or control. Owner will ask questions of front line staff, and use that information to challenge their manager. In reality, the owner is often everyones manager, which can create confusion if everyone has an extra boss to please. A successful organization needs to teach the owner that either the owner needs to learn to delegate power, or become a silent partner (think back to every dot-com and how they replaced the initiator with a seasoned CEO. The issue at this size, as you grow isn’t tech savvy or vision, it’s the ability to let go of direct authority with losing control of the company).

40-100 People. Medium Business.
Successful businesses who get to this stage have built a management structure that mostly cordons off management from front-line staff (not in a bad way: this makes sure that owner/CEO can communicate through channels, and maybe gives access, but doesn’t interfere with day to day business (they will instead talk to the department heads and figure out problems and solutions that way). Successful medium companies have found a niche that’s profitable enough for everyone to profit from working there. They are small enough that they only outsource when it makes sense (payroll, specialized marketing, etc) because they can hire quality people internally. owner/CEO has time to pursue other ideas and ventures with much less risk of burnout.

100+ People. Large Business.
My only experience with large companies are as a low-level contract employee or through case studies and magazine articles, neither of which I trust enough to build an opinion here on.