A client asked me to explain the differences between a pop-up, a pop-under, and an exit-pop. Really, to better understand what one wants, one needs to have a feel for how their own web site visitors will react. Some audiences will react well, and some will be offended. Perhaps the best way is to experiment with them to see which you’re comfortable with and which sells better. I tend to rely on direct links, myself, but that is more my style. I did try a pop-up with a poll once, and got far more respondents than I got with it as just a link, but it wasn’t a direct sales pitch.
A pop-up appears as a new (usually smaller) window, blocking the vision of a new visitor to the page so he/she is sure to notice it, and must make a decision whether to close the extra window or perhaps even buy what’s offered. I think sellers use them because they actually get some positive sales results with them, but they are very annoying to people who want to just get to the page they wanted to read, and if overused might build hostility in what would otherwise be potential customers. Most browsers, too, come with a pop-up blocker option, so if you relied solely on a pop-up, visitors might never see the ad at all. On the other hand, I suspect what PayDotCom.com is offering is a type of ‘in page’ pop-up, that looks like a new window, but isn’t, so that a browser pop-up blocker can’t work.
A pop-under is just like a pop-up, but is an extra window that pops up _under_ the page the visitor is trying to read and just sits there, so that when the visitor eventually closes his window, he’ll see it in his own good time and possibly make a positive decision then. It’s less annoying, but does require an extra click to close it, and might be susceptible to pop-up blockers as well.
An exit-pop is a pop-up that catches when the visitor is trying to navigate away from your site or close his tab or browser, and it temporarily disables the visitor’s ability to leave the page until he has seen the ad and makes a decision whether to stick around for more of the sales pitch or demand (by clicking) to leave the page. Quite obnoxious, but I hear it has some statistics for changing the action path of some visitors from “leaving” to “buying”.
And of course, a link is just a plain link
I guess it all depends how aggressive you want to be.
And it should be fun! Pop goes the weasel!