Overstock uses Coinbase for checkout and converts the majority of it to dollars immediately. They have recently begun to hold about 10% of sales made in Bitcoin as Bitcoin and have disclosed this as a risk in their latest 10-Q to investors. Bitcoin accounts for 0.25% of sales, so they're keeping 0.025% of revenue as Bitcoin.

While many may argue the prudence of such a decision (and subsequent disclosure), it's important they disclose this as their Bitcoin holdings lost about 1/2 their value in the last quarter. Any major company keeping any significant percentage of their sales revenue or cash holdings as Bitcoin would be exceedingly irresponsible.