[tyingq]

I do agree that QPX was untouchable, but I still think tech debt in competitors was a major factor. There were plenty of smart people at your competitors...I'm sure graph search occured to them. I suspect efforts to green field that were squashed...nobody wanted to throw out the hairball they had because of the existing investment. Thus, they tried to "fix" what they already had...with obviously bad results.

Edit: And, worth mentioning that your competitors wouldn't have had to be better than, or even as good as QPX. "Good enough" would have squashed several big sales, since shopping was typically bundled in with what their customers already paid.