I am preparing to really start using stumble upon as I notice I am getting more and more traffic to one blog from there.
Which is odd since I really have not used that site in a couple years or more.
Twitter is good for traffic to my blogs.
Every post I tweet out.
Facebook I just have the family page.
After I get stumble upon working I will go into getting a business page and try that for a few months.
I never use facebook to sign in on any site.
No site needs to see or know I have facebook.
Thus, I use my email and password.