If the navigates is to hard to get around they will leave very fast. Make easy to get around and each web page should link to your homepage. All web surfers get frustrated when they find a lot of dead links on a web site. You should clean them up soon as you see them. You can use spiders to find dead links on your web site.

Popups are the most hated advertisement of them all. They just wanted to read your web page, not get a face full of advertisement. If you need to make money off your site there are other ways and some bring in more cash. Slow loading pages really take to much time out of the visitors day, well at least that's the way he feels.