One of the hardest things that is faced by business is advertising. The choice of where, and how much is enough. Then finding means to show how well the advertising is paying off, depending on your choice of an advertising site you have the option to deliver coupons. Web Advertising like the newspaper becomes a low cost source for delivering verifiable coupons, if the user has a browser and a printer then you can watch that coupon walk into your business. This depends on the individual provider and what you want.
Some providers have more resources and expertise in designing web pages.
This is a question that you need to address with the provider before acquiring their services. Advertising over 200 search engines that they advertise to. Depends on your choice of words as to how effective it will be. This is the place you want to be. The problem with some of these is that they expect you to be the Web Master and HTML author using a language you don't know.