WHY PEOPLE’S PREFER TO USE USB FLASH DRIVE THAN CD-ROM’s or DVD

VS

COST EFFECTIVE
As long as businesses exist, then they will need good, cost effective marketing that reaches a wide audience. In the past, most companies relied on paper. They sent catalogs to all of their customers or handed out flyers. Then, companies tried to adapt to the computer age by distributing CD-Rom's and DVDs instead of paper products. The logic behind this transition was that people would be less likely to throw away digital media as this is clearly not the same as junk mail. Nevertheless, the smarter companies have been making the shift to promotional memory sticks. This is probably the best change yet.
The problem with CDs or DVDs is similar to the problem with the old paper products. People see them as clutter and dispose of them on a whim, often without even bothering to look at them. With USB flash drives this will never be the case. A custom USB flash drive is seen as more expensive, more useful and less disposable than a CD or DVD, so people will be hesitant to throw them away. Already, this makes flash drives a better deal than CDs or DVDs, since the goal is to create something that the average consumer will keep and view. After all, what's the point of spending money for something that people will just throw away?

DURABILITY
Custom USB drives are also more durable than CDs and DVDs, so even if they are carried around for a long time before being used, there would be no scratches or potential data loss. With a CD or DVD, a few scratches could mean the difference between viewing the media and receiving a message that the disc has been corrupted and is unusable. Even if people were to keep a CD or DVD with the intention of looking them later, throwing a purse or bag down to recklessly could ruin all of that.


REUSABLE
Custom USB drives are reusable. It's not a nice thought, but sometimes people want to keep the USB flash drive, but don't want the data. However, even to replace the data, customers have to plug the USB flash drive into their computers first, so if your catalog loads automatically, then they will see it as soon as their computer recognizes that it's there. Even if they replace the data, your brand name is still there on the USB flash drive itself serving as a constant advertisement.

WHAT ABOUT SPEED?????

Although USB Flash drives are more likely to be used by the consumers it’s doesn’t means that USB Drives are faster than CD or DVD. A research had been conducted to see which instrument are faster.

EXPERIMENT :  creating an XP SP3 USB boot disk for installation purposes

Apples to apples comparison (LEVEL ARE SAME)

 48X CD-ROM  ~7MB/s        VS      USB 1.1 stick  ~ 1.5MB/s

So From this case it shown that  USB  1.1 Stick is much more slower than CD’S. 

Credit to hazwan 

for more information please visit :- http://en.wikibooks.org/wiki/Computer_Hardware
                                                    http://en.wikipedia.org/wiki/USB_flash_drive