For the latter, bills have been paid long ago (sunk costs), titles are carried in inventory at or close to zero cost, and direct mail campaigns will create a low cost of goods sold and will be able to sustain a lower rate of response.
A browser is software that is used to access the internet. A browser lets you visit websites and do activities within them like login, view multimedia, link from one site to another, visit one page from another, print, send and receive email, among many other activities.
If you want to view web pages on different websites, you will need to use a program called a 'browser'. This acts as your door to the internet. Browsers are all slightly different, but they all allow you to 'surf' the internet and access different websites.