Currency is a feature that has been here since the release. The two currencies are "cash" and "coins" that are implemented into the website. There is currently minor bugs with the system.
The currency is at a 1:10 ratio which makes coins considerably low value.
You can use currency to buy stuff such as items in the catalog, groups or just simple bragging about being richer than the CEO according to the amount of money he had when streaming. If you have more than 5000 cash, you can earn the Gold Mine Achievement.