Since the last millennium, it is both considered rude to chain your guests that comes for a party and to open links in a new windows for your visitors on your website.

If I was an event organiser, and that one of my clients said to me "My visitors might stay a bit in my house, and by mistake walk through the exit door and leave us. To avoid that, I want you to chain them, so they won't risk leaving the party", I might try to argue that if they are able to walk out the door, chances are high they will be able to turn and walk in again if they want to come back to the party.

I might also be able to convince my client that they are very very few parties where chaining the guests is likely to improve their appreciation of the party, and that even their SM friends would be surprised, and even unhappy, to end up with handcuffs if they are going to a regular party.

I think they are enough arguments to convince almost anyone, but mostly, I would probably just say them that's illegal, and no matter what are their reasoning, you don't do that as they will end up in a jail.

However, I'm managing a web agency, and what I have to deal with are clients that want to "open links in a new windows, so my visitors don't leave my website".

On the web, the closest you have to the laws are the "web standards", and the code to open a link to a new windows is target="_blank". The latest standard xhtml suppressed it, because their general opinion was that it was not good for you (and separation of behaviour and content presentation). Unfortunately, that's not good enough, as

1. Most don't care too much about the standards anyway
2. you can do that in javascript and be standard compliant.

Beside, I thing the usability arguments are strong enough to convince them, and it goes like that:

One of the usability gurus (jakob nielsen), wrote in 1996 that it was one of the 10 mistakes, and detailled it in 1999 :

"Designers open new browser windows on the theory that it keeps users on their site. But even disregarding the user-hostile message implied in taking over the user's machine, the strategy is self-defeating since it disables the Back button which is the normal way users return to previous sites. Users often don't notice that a new window has opened, especially if they are using a small monitor where the windows are maximized to fill up the screen. So a user who tries to return to the origin will be confused by a grayed out Back button."

In the pre web 1 area, it was already considered rude to decide on the behalf of your visitors if they want to open in a new windows or not. Surely, 10 years later, they are still big enough to decide on their own.

If you think that it will hurt the success of your website, you might take the example of a little startup that did quite well without opening any link on a new window. You might visit any of the most visited sites on the world, you will see that they, as a general rule, don't open links on a new window.

Even if you're convinced they are all wrong and they would do better by opening new windows, your visitors spend most time on other websites than yours. If you don't behave like they've learn to expect by browsing on other websites, you are wrong because you don't act as they expect you to, you will annoy your visitors. In such a case, the goal is to do what the visitor wants, if you don't you don't do what they want, and if you don't do what they want, they'll leave.

As Nielsen wrote it, opening on a new window is counter productive if you want them to stay on your website, because they can't use the back button to come back to your site if they want to. Visitors know how to use the back button, they know how to come back to your site if they want to.

I might be wrong, but overtime, I reached the conclusion that the "open in a new window" is built on disturbing assumptions.

The first is that the visitors are dumb enough to be tricked to stay on your site, even if they want to leave. In general, I wouldn't recommend to assume your visitors are stupid, but even for the less tech savvy among them, they will know how to close the window that contains your browser, or leave your site open in the background hidden under another window and not touch it anymore. Worse case scenario, they will be able to switch off the computer. If a visitor don't want to visit your site anymore, and short of holding a gun on his head, there isn't much you can do to force him to read you.

If your content isn't good enough by itself to keep the visitors on your site, they will leave, either by following one of the links you put on your content, or by going back to the search engine they use (and that doesn't bother them with opening in new windows). The best way of keeping your visitors is to provide good content. You can't compensate that by tricks to force them to stay on your site.

No matter what, every single visitor that arrived on your site will leave it. Usually, that visit is only a few pages long anyway, no matter if you open in a new link or not. Big news: this isn't a problem at all!You should focus on providing them a pleasant experience, and provide them quickly the information they where looking for, and suggest them there is more. If you've provided them what they came for, you're good, you've done it. If you provide them a more detailed information, as a link to another site, that's even better. Let them go, you don't want to screw that by finishing their visit on a tasteless note. Let them go.

If you've done that, you've done the best you can. If you focus on that, they will leave, but they will remember your site, come back another time or mention it to someone else. People came to your site to find a specific information, provide it to them and let them leave

http://www.useit.com/alertbox/990530.html

http://www.sitepoint.com/article/beware-opening-links-new-window/

http://valhallaisland.com/blog/2008/target-blank/