"Bloggers with advertising are more sophisticated in terms of their use of tools, advertising platforms and even events to build reader loyalty. They also invest more resources (both time and money) in their blogs. "
Apparently those bloggers who choose to not have advertising on their blogs have a lack of interest in it, and don't want their blog to look too crowded (that was actually one of my reasons).
One in four bloggers uses three or more means of advertising.
"...two in three have contextual ads (such as Google AdSense). One-third of bloggers have affiliate advertising on their blog. One in five negotiate directly with advertisers and one in ten sell advertising through a blog ad network."
"The average annual blogger revenue is more than $6,000. However, this is skewed by the top 1% of bloggers who earn $200k+." - wow!
But...they invest an average of $1,800 annually in their blogs. - not bad really.
Most high earning bloggers are male, work for themselves, write corporate blogs, earn about $19,000 a year.
I think they deserve the money, it's hard work and takes a lot of time to keep a blog. I'm not sure I could do it without the love of the topic!