There are many big sites that accept bitcoin but are not related, an example being dell and dish who both accept bitcoin.
But I guess those sites accept Bitcoin as an experiment, but make their living out of fiat money.
The whole point is that when I think about bitcoin, the only people I know who admit to make money out of it are gamblers and speculators.
And their final goal is to use bitcoin as a temporary method to increase their fiat money. That is a symptom of failure.
Small companies like shops are really skeptical and some of them declare to have lost money by accepting bitcoin,
If real and honest work is being exchanged for bitcoin, for me that is a symptom of success.
Most wil keep cashing out in fiat due the fact Bitcoin is still in its infancy. As merchant adoption arises it will be more and more pointless to cash out for deprecating fiat.