Demographics about Web abound. You may find such data helpful. In general, when I look at research available, I get a feeling it's incomplete. The Web is so vast, I don't think it's possible to find a small representative sample from which significant results can be obtained that reflect whole. In end, what is reported with numbers may not matter to you, even though source is impeccable.
Numbers Don't Always Work
For example, it has been reported that 330 million people are "on Web." I have not read closely enough to know if this means daily, occasionally, or somewhere in between. To me it doesn't matter.
Even if this number were doubled, it would still mean nothing to me. I am interested in reaching an extremely small fraction of web users. The implication I've been seeing in spam messages of late is that I can reach all 330 million people. This is a lie. But there would be no gain in trying to do so in any case.
Honest Numbers Can Be Wrong
I recently read a report that of nearly 100,000 spam messages received by one firm, about a third were promoting po-rn sites. (I used a hyphen in hopes of ducking blocking software.) What does this mean?
Numbers are funny. I never doubt such reports from respectable firms or people. But I am always skeptical about numbers themselves. Sure, those were results obtained. I will accept this without hesitation. But they often do not seem in accord with my experience.
I get lots and lots of spam. Less than 3% is po-rn related. Do I thus conclude report was wrong? That they were lying for some devious purpose?
Not at all. It only means their sample of email received was not representative of what I receive. In like fashion, it is doubtful my email is typical of yours.
100,000 spams messages is a very small percentage of what is mailed each day. It is so small, results from this sample have very little, if any significance. These results were obtained, that's true. But they may have no meaning relative to you.
Leave particulars of demographics to those keen on topic. Your best plan is to ignore such numbers and focus on interactivity with readers and visitors. In every way you can, seek input, then derive your own demographics from it.
Your Log Files Can Mislead
Recently I was chatting with a fellow who was having trouble getting a page to load under a specific condition in Netscape. Since he uses Internet Explorer, which handled this case correctly, he hadn't noticed problem until I pointed it out.
When I did, he commented, "Hey, I don't need to worry. Only 5% of my visitors are using Netscape." This fellow is wrong in two ways.
Of visitors to my site, over 40% are using Netscape. So have I got it wrong? Or is fellow reporting 5% wrong? Neither of us is. We are both reporting accurately.