Everyone is selling something. It might be a product, a service, a download, an idea, or a worthy cause.
Whatever you’re selling, it’s got to be worth the price. (And never
forget that reader attention is a valuable commodity that’s in strictly
limited supply.)
Whether you’re asking for dollars, euros, yen, or valuable time and
attention, you’ve got to deliver something that towers above your asking
price.
coutersy of http://www.copyblogger.com