Best suited to executives with frequent travels, this technology can be of great help. Indoors also one can use wireless mobile broadband service. The basic advantage apart from its location independent use is ease of access and high speed of internet.
Now consider the aspect of cost which one needs to pay for this service. Apart from the cost of the USB one needs to get registered for some scheme or plan for broadband with any Internet Service Provider. Many packages are available these days from small plan of use to a yearly scheme. As per the use and cost effectiveness, one can select the broadband plan. The cost of the service depends on many factors viz. usage, speed, plan opted etc.
Flip side of this technology is that one spends more than what one thinks he does. Apart from the cost of the dongle, the registration charge of the ISP is always there. Companies have to be paid with the installation charges. Also certain plans which seem cost effective might not give unaltered service to the user.
Summarizing, mobile broadband is a good option if used wisely as per the needs and convenience also taking into account the total cost of the service.