This thread is something of a compromise. Personally, I think it only serves two purposes. Firstly, it provides a farming resource for spammers and other address collectors. Secondly, it is a repository for all the similiar posts that would otherwise clutter up the forum. I don't disagree with some of the "usefulness" comments, however if it serves a perception of usefulness, then that is fine.
I have always thought that an employer worth working for, would be one who could afford to place an advertisement without violating the site rules on advertising. In other words if they can't afford an advert, what would make somebody feel they were likely to be a quality employer? To that end we don't permit the practice, and are quick to dissolve any breaches as they arise.
For people wishing to place their own details, I doubt it is likely to serve any useful purpose, but provided they are reasonably circumspect with regard to those details, there is little chance of any harm resulting.
There are only one or two forums on the site that permit this type of thread. I am not sure that will continue in the future, but for the meantime.....