They learn who is visiting, what visitors like and don't like about the web site, and where their visitors live. The information is used to improve the content and ease of use of the web site, and, in the case of commercial web sites, help marketers more accurately target the marketing of their products. Kid-oriented web sites and chat rooms often legitimately ask for personal information to screen those who use the site to maintain a safe and fun environment. However, you and your child should always ask yourselves how much and what kind of personal information is appropriate to give to strangers when registering or signing a guest book at a web site. You should always consider the purpose for which the information is needed, who runs the web site, whether the personal information provided is absolutely necessary, and whether it could be misused.
Kids love to register for contests, to gain access to web site features, or to get other benefits.
Teach your child to be aware of the potential problems, what information can be appropriately provided, and what should be kept private. For example, if your daughter is already on every mailing list Lego has ever created, you may not mind her getting catalogs or other promotional material from Lego, since she is already on Lego's mailing lists. So when she visits the Lego web site, you may be more likely to allow her to register your e-mail and mailing addresses to participate in online contests. However, no web site manager truly needs your address, and certainly no one needs to know your telephone number. If you follow commonsense and your children are clear about what you expect of them, your children will almost certainly be safe on the internet.