This week is an absolutely crucial week for BlackBerry(BB 0.70%). The company's powerful new handset, the Z10, was launched on AT&T (T 0.16%) on Friday, and it's due to launch with Verizon (VZ -0.57%) and T-Mobile this week. In this video, Motley Fool tech and telecom analyst Andrew Tonner tells investors why a big win for the company here is vital as it struggles to stay relevant in a market dominated by iOS and Android phones. Andrew also gives us a preliminary look at how the company is performing in terms of sales.