You are searching for the keywords related to your business, but your site is far, really far from the first pages of search results.
Reasons may vary, your website may be new, there is a lot of competition in that market, you don't have enough followers in social media, ...
So you decide to spend some money to advertise your site in the first page of search results. And you hope that some day your business will be important enough to rank in the first places naturally. But this will only happen if your business becomes a big brand, then you won't need to pay for advertising any more. But this is a very difficult goal for most of the businesses, as they are small or medium size companies, with local reach only.
At the moment you'll stop paying for search ads, your site will end disappearing into hundreds of search results.
