It is said that during a gold rush, the people who make the real money are the ones selling the spades.

The same appears to be true with Bitcoin, judging by the whacking great revenues announced by a firm which makes computers dedicated to mining the cryptocurrency.

KnCMiner, a Swedish manufacturer of Bitcoin mining machines, told us it made $3m worth of sales in just four days earlier this month.

During this bumper sales period, which started on November 7th and ended on the 10th, the value of Bitcoin skyrocketed from $264 to $336.

KnCMiner was founded in April this year and is one of the victors in what it described as a "digital gold rush”.

“While we have seen a significant increase in demand for our line of machines from the last quarter to this one, what happened in the last four days has been unprecedented for us, maybe unprecedented anywhere in the Bitcoin mining industry, said KnCMiner CEO Andreas Kennemar.

"In four short days, we pushed $3m of equipment out the door. The increased activity around Bitcoin in just half a week undoubtedly had a sizable impact on our sales. We’re now focusing on doing everything we can to meet the demand we expect we will continue to receive, especially as Bitcoin’s popularity continues to soar.”

KnCMiner also flogged $600,000 worth of upgrade modules to miners who had already bought rigs. In total, the Swedish firm has managed $29m worth of sales and has shipped its gear to 120 countries. All in all, the seven-month-old firm has sold 5,000 mining machines.

Bticoin mining rigs are computers dedicated to generating new Bitcoins by solving complex mathematical problems and hashing them, which process is explained in this article. The hash stage is necessary to ensure the validity of the currency – full technical details are available on the Bitcoin website.

It used to be the case that an ordinary graphics processing unit (GPU) was fast enough to solve the hashes, but as more Bitcoins are created the successful hashes necessary to generate them have been getting more and more difficult, leading to a need for dedicated mining machines.

Bitcoin was created by “Satoshi Nakamoto”, a shadowy and (not quite) unidentified character who was never heard of before the cryptocurrency's creation. ®