In what world was Netscape a failure? Made some people an awful lot of money and then gave us Firefox... Pretty far from failure
Netscape existed as the internet was coming into existence. You used to have to buy a physical copy in the store to install it. People barely knew how to use their computers so the activation cost for bypassing their "pay wall" was high enough.
The open sourcing of Netscape 5.0 happened in early 1998, and AOL purchased Netscape later that year. Firebird/Firefox came a few years later.
That is not true. They also made it available to download over the internet free of charge (and, as others said, they licensed it to ISPs to distribute to their customers). You were expected to buy a commercial license if you used it for business, though. Practically everyone had a copy of it in 1997 and used it as their primary browser, paid or not, until Microsoft shipped Internet Explorer.
Second, it depends on what you define as success and failure. Netscape made its pre-IPO shareholders money if they timed their stock sales right. But the stock didn't go up because the company was profitable. It went up along with every other dot-com stock until the 2000-2002 crash, based on hopes and dreams, not fundamentals. The company never turned anywhere near close to a profit.
To me, a successful company is one that makes a sustainable profit based on its business fundamentals, not one that makes its founders and early investors rich in an investment bubble.
[1] Correction: Netscape did charge for the browser if used in a commercial context, but few people actually paid up.