Dropbox just threw its chief competitor under the bus to prove its business is doing fine

Dropbox wants you to know its business is doing fine - so much so that it just threw its biggest competitor under the bus to make a point.

At its first-ever user conference called Dropbox Open on Wednesday, Dropbox CEO Drew Houston shared some updated numbers about its business.

Dropbox now has more than 400 million total users, and 8 million businesses using it in one form or another, he said.

Houston also pointed out Dropbox is seeing over 150,000 paying business customers now, of which 50,000 came in the last 10 months.

Houston made a point to stress that the 50,000 new paying business customer figure over the last 10 months is more than what some of its competitors have been able to sign up in its entire history.

"In the last year alone, we added more business customers than they have in their life time. That speaks to the power of our model," Houston said.

Houston didn't specifically mention which company he was referring to, but it's not hard to guess who it was: Box.

Box has always been compared to Dropbox as its main arch-rival because they basically offer the same cloud file storage service, but only towards different customers: Dropbox is mostly for regular consumers, while Box is almost exclusively for business customers.

Box states on its website, "Box enables secure collaboration and content management for more than 50,000 paying customers globally, which include over 52% of the Fortune 500 and over 28% of the Global 2000."

Although an impressive number, it's hard to tell how much sales the 50,000 new paying business customers are actually driving towards Drobpox's top line revenue, because it could include either a small 3-team company or a 300,000 seat deal with a big company like GE.

In any case, it proves that Dropbox for Business is scaling fast, and its strategy to leverage its massive consumer base to sign up more business customers may be working.

Dropbox has seen massive growth since its launch in 2007, raising over $1.1 billion at a $10 billion valuation. Its user numbers have blown up, reaching 400 million worldwide.

But most of its users are known to be free users, and in order to boost its sales, Dropbox has lately been focusing on adding more business customers. In order to target business users, Dropbox launched Dropbox for Business two years ago, but many question how well it's really been doing lately.