Providers pay to give you the information. Instead of shoving a mess of advertisements through newsgroups, they have to pay someone for space on a machine to store their information. They also have to pay programmers to format the information, connect the company to the Internet properly, and maintain the services. It's completely voluntary. It's up to a user to choose to look at a page or not.
Companies can get information about the people who look at their pages.
Putting a fill-in form on a set of Web pages is trivial. Another option is to use a statistics-gathering program, which can find out exactly how many times a page was accessed from what Internet address. The number of people on the Internet is growing. Providers can reach thousands of people per day for less than the cost of a major marketing study and mass mailing. Thousands of companies put up new Web services every month.