Most of the people tend to look at a few factors when you buy an SD card for your camera or your cell phone either: storage and the price.
Today there are more things which look before purchasing this type of devices, even more so considering that increasingly more manufacturers launch mobile devices compatible with this technology storage capabilities. There is where we must begin to look our new acquisition has data transfer fast enough capability to run applications stored in them consistently.
The first announced class is the A1, which has been defined as capable of processing 10 MB per second. SD class 1 and class 10 cards are currently able to be at the height of that standard, but this new classification is to help clarify and simplify things for consumers.
It is expected that come out more classes in the future, but for now, not only we must look in the storage, but also be A1, or at least class 10, that goes clearly specified on the labelling.