I reading news and searching a coding for any programming languages, searching a forums, articles, blogs, press release etc.
Internet = 80% Working + 20% Googling + 20% Hearing Internet Radio.. what?? 120% yes, because the hearing part is called a multi-threaded task
I use Internet for reading ebooks, own micro niche blogs (AdSense is awesome :-D) and reading some forums. But it depends - sometimes I do other things.
While surfing most of the time, the attention is divided, and I don't read as thoroughly when surfing. I skim and scan a lot more. Look for certain info instead of trying to absorb everything. Surfing is more useful, but less rewarding. Surfing is more educational too, for me.