CryptoTab is a site for mining bitcoin through an extension on your browser. There is also an internet browser to mine 8x faster than the extension. The site has a really interesting sponsorship system, on 10 levels, to create real networks! Earning your first bitcoins has never been easier, especially thanks to the referral system. This is a really serious site that pays, and can become really super profitable, if we take time to find referrals.