What happens to great tech companies or tech products that make them become losers?

What happens to great tech companies or tech products that make them become losers? E.g. Adobe (Flash going down, replaced by HTML 5), Altavista (once #1 searcher, finally dead on March 2011), AOL, AT&T (lost its monopoly on iPhone), Barnes & Noble (Nook was not a sucess), Google's Chromebook, Google Labs, Google Health, Google Knot, HP's WebOS, brick and mortar shops like CompUSA and Circuit City, MySpace, Netflix losing market, Nokia (once #1), Olympus, RIM (Blackberry and Playbook), Sony (Playstation Network failures and Tablet S bad results), Dell (Streak tablet), Android 7" tablets in general, Yahoo!, Zune HD by Microsoft. Which technological, marketing, financial and research factors made them fail.

Answer: http://qr.ae/RIVmu on @Quora
http://qr.ae/RIVmu