Let's start with a simple idea. In physics, we know that all objects with mass have a gravitational pull on other objects with mass. We know that the bigger the mass, the greater the pull. And, the closer to an object you are, the greater that pull.
If you are in a space ship far from earth, earth will exert very little pull on your tiny craft. But as you get closer, earth's gravity will begin to draw you in. Get too close and earth will pull you in to the surface for a nasty crash unless you have sufficient energy to escape the pull of gravity.
Big businesses, like Wally World have a lot of mass and therefore a lot of pull. If Wally opens a store in your town, his massive store will suck the business right in to his store and away from yours.
Here's the secret. Mass isn't size. Mass is about density AND size. Wally is going to have great size but very poor density. In other words, Wally World has a big shoe department but you won't get a good selection of quality shoes---just a lot of cheap shoes. If you own a shoe store trying to out-pull Wally, increase your density. If you have the only selection of fine quality athletic footwear in your area, you will get all the fine quality athletic footwear business. Density. By increasing the density of high end athletic footwear in your store, you can achieve a greater mass, and pull, than Wally World!