I just wrote a blog post about how Gartner never said that 71% of tape restores fail. They never said anything like it. Another statistic that is often quoted is "The Yankee Group said that 54% of tape restores fail." Guess what? They never said that, either.
What they did say in a 2004 paper is that 40.7% of 362 IT executives believed that they had suffered at least one restore failure in the previous year due to tape unreliability. That's not even close to saying htat 42% of all tape restores fail, but who need truth, right?
Also, I'd like to throw out that these were IT executives. What this stat really means is that 40.7% of them were told that they had restores that failed in the previous years due to bad tapes. That's not quite the same thing as it actually happening. How many backup people even know that the reason for their failure is their own misconfiguration? And if they did, how many of them would admit that to their boss, rather than saying "the dang tape failed again."
Now the only statistic left is the Strategic Research one, but I can't find anything on that one.
It appears that at least 66% of all tape statistics are made up. 😉