An auto-responder, after initial creation, is a hands-free marketing tool. If there is a contact email link on the company's web site, there should be an auto-responder attached to it. An auto-responder is a pre-written 'canned' reply that is sent immediately after a person sends an email to a specified address. It is fast response with notation, where necessary, that a prompt response will be coming and more marketing splash about the company.
Auto-responders can be used with reports. Produce an email report targeted to the niche audience. Have a link on the company site to the report so that every time a visitor requests a report, data is collected from him/her and stored for future mailings. This creates one more chance to sell the company's services/products and increases the database for future marketing efforts. It also will aid in site statistics of visitor profiling. These little tools can be invaluable assets for data mining for many departments within a company.
Series of autoresponders are multiple emails that are pre-written and set up to send out at different intervals after the initial immediate email is sent.
Affilate marketing - follow ups of product uses
Create series of emails sell different products in a line
Teaching courses sending one per week.
Free Email book delivery with follow-up tips
Joint Venture Partners - if you have a group of JVs, you can send one by one their introductions to your list.