I've considered a "day in the life" blog article, a kind of minute-by-minute day in the life of a game store owner. I honestly don't have time for that level of documentation, but I did want to share what game store owners do. If you've worked at a retail store or even managed a retail store, you've performed a subset of the owners job.
All of the tasks performed at a game store can be divided into the categories of clerk, manager or owner. The owner of a small store does all these tasks. That's what I did my first three years at the old store, everything from vacuuming to finance. I'm lucky enough with the larger store to be able to delegate a lot of my clerk duties. Eventually I want to grow large enough to delegate my manager responsibilities too.
Here's a brief overview of tasks:
Clerks: Loss prevention, sales, cleaning
Managers: Loss prevention, sales, purchasing, receiving, payroll, scheduling, displays, management of clerks
Owners: Loss prevention, sales, accounting, marketing, business strategy, management of managers
Dave Wallace has an excellent Manager's Handbook that goes into great detail.
Note that the key tasks of loss prevention and sales are done by everyone. Everyone sells unless the business is so large that the owners other responsibilities don't allow for it. Few game stores ever get to that level. Part of sales is preventing stuff from walking away, so loss prevention is always key. An owner may approach loss prevention more strategically, like planning regular inventories or changing product placement.
When I wear my owner hat I'm usually paying bills or figuring out finances, dealing with vendors, writing policies or procedures, developing my marketing plan or event schedule, or general business strategy projects. The main reason I think businesses fail is that owner tasks are never given the proper time they deserve. I know they often seem like a nuisance, divorced from day-to-day operations. As E-Myth Revisited says, "work on your business instead of in you business."
If you want to own a successful game store, own one because you love the idea of doing owners tasks, not because you love clerk or manager tasks. Definitely don't plan to own one if clerk and manager responsibilities seem beneath you. The brutal shock to your ego could be life threatening.
When I began my business, I fully intended to do 100% owners tasks. I thought I would be in the back room putting my plans for empire into play. I would hire clerks and managers to do the dirty work. The reality is an owner needs to understand every element of the business before they can develop policies to hand them off, if they're lucky enough to do so. The dirty work is the business. Learning and development take time and experience. Unless you're a genius or rich, you will have to quit your day job.
You also have to look at the list of owners tasks and ask yourself what you're getting our of such a job. You've created a business management position without the payoff associated with such a high stress, knowledge-based positions. As many have observed, anyone successful in this business could easily find themselves a job making significantly more money elsewhere. Most entrepreneurs, so I'm told, thrive on the owners tasks and have the trait of being nearly incapable of working for other people.
Here's a good article on Opening a Game Store.