Watch out. Be careful. Make sure it's what you want.

Comic stores popping up on a couple of industry sites and telling all about their expansion plans.

I have some thoughts on that.

Over-expansion is one of the classic mistakes for small businesses to make for a couple of reasons.

1.) Basing your expansions on current booming sales can mislead you. Booming sales always level off eventually. 

Mean reversion, or reversion to the mean, is a theory used in finance that suggests that asset price volatility and historical returns eventually will revert to the long-run mean or average level of the entire dataset. Investopedia.

When it regresses to the mean, you're stuck with higher costs, but the sales no longer justify them.

2.) It may not be what you really want. 

Look, it's the American way. Success breeds success. You're offered a promotion, you take it whether you like your current job or not.

I came up with a corollary to the "Peter Principle." Let's call it the Duncan Principle just for fun. If the Peter Principle is that an employee will be promoted to their level of incompetence, then the Duncan Principle is that a business will expand to its level of incompetence.

So, yeah, when I opened four stores I discovered that I didn't have the experience or capital to pull it off.

But even more importantly, I discovered that being a manager behind the scenes, managing a roster of employees, and crunching numbers wasn't what I really wanted. I had to remember why I'd gotten into the business in the first place--to hang out with people and enjoy it. 

So I inserted myself into the conversation to say, "Watch out. Be careful. Make sure it's what you want.