Email doesn't need postage, right? Is that old hoax about the postal service charging per message finally coming true? Not really. But PostageApp may be a service worth paying for if you want to send email from your application.
It is not uncommon for e-shoppers to create a cart on a website without the intention of making an immediate purchase. The motives behind abandoning a cart can vary; what matters is how companies take advantage of the information that can be gained with each cart that is left behind. Rejoiner is a company that helps online retailers capture, analyze and recover abandoned shopping carts. The company accomplishes this with their Rejoiner API.