MailChimp is a freemium email marketing tool. Similar to Wufoo, they offer a free plan (good through 2,000 contacts). A bit of background: MailChimp grew their business significantly when they decided to go freemium. How? At the bottom of every email, it would say something like Powered by MailChimp. Every customer email sent helped to spread the word. It created a kind of viral loop.
Prospecting and marketing are all the things you do to get people into the first of your sales funnel stages. Note that stages are broken into two or more steps wherever possible. A demo could be called a single stage, but in real life it involves a lot of things: contacting the customer, sending reminders, doing the demo, and then following up. Whatever your own sales stages look like, the support you need in managing them will be the same.