Helping customers find you online.
In the old days, you could tack a wooden sign above your door, announcing to passing town folk that Ye Olde Taverne was open for business. To extend your reach a little further afield, you could pay people to hand out fliers.
For some small businesses today, this sort of local advertising is enough. If you only need to attract customers who live in your vicinity, then a local search-engine optimisation (SEO) campaign is for you.
This approach falls short, however, if you make a significant chunk of your revenue through e-commerce. More and more businesses today exist primarily online. For that reason, they rely heavily on their online shop being found by people who are looking for products or services on search engines such as Google.