An autoresponder is actually the technology you can use to stay in touch with your email subscribers. There is actually a bit more involved, rather than just thinking that using an autoresponder will make you money. Although, the formula is straightforward:
1. Build an email list.
2. Build a relationship with subscribers (which can be done with the help of an autoresponder.
3. Recommend products and services to your subscribers ($$).
The key is in step #2. With the help of an autoresponder, you can build an email follow up sequence designed to create trust with your subscribers. Only then would they feel comfortable buying from you (or buying products you recommend).
So you see, an autoresponder is only a small component in the formula to making money online.