OK, prior to this problem I'd visit certain forum and image sharing websites and usually have a few different tabs open, for different sections of the site or different topics. I like to multi-task.

Now all was fine for what seemed to be quite a long time, but then something changed.

What I'm finding is that when I'm visiting certain sites that were fine before, I'm now seeing very painful lag. If I'm typing a response to a post, it will start out fine, but then... the lag hits. I type and nothing happens. No control. Can't select text. No response to buttons. The browser activity icon is spinning. Then it "catches up" for a moment. Sometimes it's a quick catch up, other times things just go one character per second or even slower. A really prime example of horrible performance is PhotoBucket.com. I'd been using this photo sharing website for years, with no problems. But now... their interface becomes so slow, I've found I can't really use it effectively (I'm now using PostImg.org for hosting new image files). It seems like it is due to heavy ads with inefficient or high bandwidth scripting. That's just my guess.

With forum websites, I'm finding this tends to happen sooner if I have multiple tabs open on the site. If I reduce to one, it doesn't seem to be a problem, but then eventually happens. I will see in my browser status bar, references to all kinds of 3rd party sites. They look to be ad related sites. It's common for pages on the site to load video ads as well (instead of just picture ads).

Now if I kill the browser tab and start again, it will seem to be fine at first... but then get progressively worse. Sometimes the browser will say the page is not responding, while other times it will complain that a script is running terribly slow.

I ran Malwarebytes Anti-Malware. I don't have anything on my system. It's clean.

Is this a problem with some websites in general? That in order to try maximizing ad related profits, they're stacking and enriching pages to deliver more ad content, some with heavy scripting included?

I'm just trying to understand what's going on... because I don't visit malicious sites and don't find anything wrong with my software situation otherwise.