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.
The first web browser ever written was called WorldWideWeb, and it was created by a man named Tim Berners-Lee. While this was the very first web browser, it was not widely used, and was only available for the NeXT platform. The first widely-used web browser was Mosaic by Marc Andreessen and Eric Bina at the NCSA at the University of Illinois.