As a Web user, I urge Web site developers to return to "keep it simple". In particular, multi-page applications are better, easier to understand, than single page applications which tend to be confusing. Treat the pages of the site more like the pages of a book -- those pages don't change as I'm trying to read the book.

Net, a single page application looks to me like it has no pages at all, just a lot of confusion where I don't know where I stand, what is the state of my visit, something I can't meaningfully copy or save.

Use big 100% black fonts on a white background. In particular, note that about 25% of men are partially red-green color blind. So, if insist on using colors, avoid using both red and green on the same page.

Have both vertical and horizontal scroll bars. Never omit either the vertical or the horizontal scroll bars. Accept no substitutes.

Similarly, never have a row of images or other blocks of content that scroll off and on the screen left or right via little arrows. With that scrolling, there's no real page I can have in mind.

Don't have parts of the page moving or coming and going without explicit user requests. Such Web pages are a good reason just to leave the site. Or, maybe I DO want to look at some of that content -- nope, soon it's jerked from me and gone. Bummer.

Don't assume that the user will display the pages at full screen -- often can't have that because need other windows open for the purpose of visiting the Web site at all.

Don't cover up what I'm trying to read: So, cut way back on popups, pull-downs, overlays, etc.

Design the Web page HTML so that I can save the page and later, without an Internet connection, still have my Web browser display the page correctly. Such saving can be crucial for pages where I've done something important, say, pages summarizing a purchase I just made.

Conserve the crucial, vertical space: So, get rid of banners that overlay the content, take up a lot of the vertical space, and come and go as I scroll the page up and down. Apparently as people saw how to do that, doing it became popular as if it were a good idea -- it was a fad and a bad idea. Don't do it. Quanta magazine has done a lot with such banners, and it has seriously hurt the usability of their site.

Now commonly a lot of Web pages have been done with some fancy work with JavaScript and require me to take several actions just to get to the content. I've had more than enough: When I see such a page, with nearly no exceptions, I just leave the Web site. I'm gone, out'a there.

I commonly have the mouse pointer on the content of the page as I scroll the page, and some sites track the mouse pointer and, then, generate lots of popups that cover up the content I'm trying to scroll and read. No matter what, almost certainly, I regard any popup I have not explicitly requested as a big interruption in my work, a big waste of my time, a big frustration, something I really HATE, and a good reason just to leave the site. Tracking my mouse pointer and responding with a popup I didn't request is doing me a favor based on some assumptions: To me, it's not a favor. In general, just do not make assumptions and then do me automatic, unrequested favors by interrupting my effort to read the content of the site. Cut way back on unrequested favors. Wikipedia and Disqus both do a lot of mouse tracking and popup favors, and I hate both of them for it.

Just keep it simple, e.g., so I can see the real content the site does have and I came to see. Just because it is possible to insult, interrupt, irritate, infuriate, and frustrate me does not make it a good idea.