Head's up Google Drive, Box and Dropbox: Redmond is cutting the price of cloud storage to, well, zero. Microsoft is currently offering online users 100 GB of cloud storage free for two years through its OneDrive service. The promotion is designed to introduce users to the company's online offerings as well as incentivise them to use the Bing search engine. 

To claim the free cloud storage, users have to first sign up for Bing Rewards, Microsoft's loyalty program that gives users prizes, such as gift cards, for using the Bing search engine. Once signed up, users can claim the 100 GB special, which will be instantly alloted into their OneDrive accounts. Users do not have to switch to Bing permanently to keep the free storage, but of course, Microsoft is hoping some will. After two years, the deal will end and users will have the option to remove their data or pay for continued service, Microsoft told the International Business Times. 

Normally, Microsoft chargers $1.99 per month for that much storage, making the deal one worth $48 total. In this case, the tech giant is opting to give users two years worth of free service in hopes that once it expires in 2017, users will become paying subscribers and, more importantly, loyal to Microsoft.

The promotion is an attempt to poach users from Google, which is the king of online search and offers cloud storage through its Google Drive service, but it will likely have a bigger impact on cloud storage services like Dropbox and Box. Those companies' businesses rely entirely on selling cloud storage plans, but cloud storage is increasingly commoditized every time companies like Microsoft, Google and Apple slash their prices or give bulks of storage away for free. 

When Google cut the prices of its Drive service last year Dropbox responded by doing the same, so it'll be interesting to see if the startup reacts similarly to Microsoft's new deal. As for Box, which began trading publicly last month, Microsoft's promotion was not received well by investors -- the company's stock price is down more than 3 percent on the day.