The travel site Expedia just announced it will begin accepting bitcoin, the virtual currency that approximates cash on the internet, for hotel bookings, making it one of the largest and best-known retailers to do so.

Expedia follows Overstock, which announced bitcoin support in January, and Dish Network, which announced bitcoin support last month. Expedia is about twice the size of Overstock and about half the size of Dish by revenue.

The company is working with Coinbase, a startup that helps merchants seamlessly accept bitcoin just as if it were any other currency. Because of Coinbase and its competitors, we're likely to see more and more big companies make similar announcements.

Coinbase and its competitors are driving adoption

Overstock claims to have done more than $1.6 million in bitcoin transactions so far, suggesting the market is still relatively small. It's still early enough that retailers may see a marketing boost by moving to accept the five-year-old currency.

Expedia decided to start accepting bitcoin just for hotels because it already has a flexible payments system in place for those bookings. If the experiment is successful, it may add bitcoin support for flights and other types of bookings.