Landing pages are highly-customized pages, separate from your main marketing site, that allows your customers to find you based on exactly what they are searching for.
It is very difficult to have your primary marketing site focus on all the keywords necessary to attract customers to all your products. Landing pages help you accomplish this.
Regardless of what your potential customers are searching for, they will find you.
Landing pages allow you to create great targets for marketing campaigns to convince a client to make a specific action. That action can be a purchase or even to sign up for a free consultation.
Landing pages are very effective at presenting special promotions with or without paid advertising.
Since landing pages can focus on one product or service it is often to convince the user to signup or execute a purchase.