Usb Speakers advise

[tictok1]

Hey, what are the pros and cons of a usb powered speaker set. Im thinking of buying these speakers http://www.pcworld.ie/Product/ESSENTIALS-PSP20B11-20-PC-Speakers/306371/8.13 . I wanted to know what the pros and cons are of having a usb piwered speakers over normal speakers and also will it take a lot of power from my psu? The speakers say it uses 3 W, my psu is a 500 watt psu running athlon II x2 processor, 4 gb ram, radeon hd 7750 and fans and light on case.
Thanks

 

[clutchc]

They're OK if you don't need much sound. USB 2.0 will only provide up to 1/2amp @ 5V, so it's no big deal to the PSU.
I imagine the sound will be weak and thin. Good enough to listen to youtube videos.