Buying Stumbleupon traffic is safe and usefull?

[shreeharisg]

Some webmaster suggest that buying stumbleupon traffic is useful for starter of blogger or website owner. Give your opinion about stumbleupon traffic. Is it adsense safe?

[naeemgari]

I would not recommend buying stumbleupon traffic. It has a high risk of being considered as invalid traffic which violates Google Adsense guidelines.

[saichavhan]

It is not safe site