If your Internet web site wants to boost its profits then an autoresponder is absolutely necessary for your long-term prosperity. Collecting the email addresses of customers and visitors is fundamental to be able to keep in touch with them. It is much easier and less expensive to keep a customer and to sell more products to that customer than it is to develop a new customer from scratch.
For this a simple email software will not do. The reason is that email, such as Outlook or what is obtainable from a free service like Yahoo, requires that you manually construct each email and send it. While you can use groups of email addresses to send each person on your list a message, an autoresponder makes this much easier.
Unlike a 'vacation' autoresponder that sends a one-time message to people letting them know you are not provided, a sequential autoresponder lets you store an unlimited myriad of pre-created messages to be sent. What this means is that you can construct messages to be automatically sent 1 day, 1 week, 1 month, and so on after a person signs up.
For example, what if you want to send someone a particular message the day after they sign up. With usual email you have to manually send that message to each individual subscriber the day after they sign up. But with an autoresponder you only need to set this up once.
Thus, if Adam signs up for your newsletter on Monday he will effortlessly receive your communication on Tuesday. No need to keep track of his sign up, email address, and send him the message. Then if Eve signs up on Thursday she will automatically receive your message on Friday. That makes your life much simpler, especially if you get a large number of subscribers and messages you want to send.
With most autoresponders, you can also broadcast a new communication to all current subscribers, as you would with your home email account, anytime you want. So you do not lose functionality by using an autoresponder. But you definitely gain an important amount of automation that will save you a lot of time.