A pingback is a notification from another website that your site has been updated. It can happen in a number of ways. You could ping a ping service, which will then notify its subscribers that your blog has been updated. Services like Technorati.com and BlogCatalog usually fall into this category.
Another type of pingback is when you link to another blog. That blog owner is notified of your link through a pingback.
Still, another type of pingback is when you bookmark your website at one of the many social bookmarking services available online. Those services will pingback to your blog because, after all, they are linking to you.
A pingback usually appears in your comments. In WordPress, you’ll get a notification in the Admin area of your blog platform letting you know that you have a comment, or pingback. You can either approve it, delete it, or mark it as spam. How you classify a pingback from a particular URL may determine how other pingbacks from the same URL are treated in the future. If you flag a pingback as spam then it may be picked up by your spam filter if it ever happens again. Just delete it and it’s gone.
So what should you do with those pingbacks? It depends.
Generally, you don’t have to do anything with ping services. They take care of themselves. You should have a list of ping services that you ping every time you update your blog. That distributes your blog posts around a little on the web, important for marketing.
If you get a pingback from another blogger that has linked to you, it’s usually a good idea to approve those. But there are times when you may not want to. If the blogger is a competitor and you have made an editorial decision not to link to competitors then you might decide to delete such pingbacks. On the other hand, many blogs link back and forth to and from competitors and it benefits both of them. Another reason you might not want to approve these pingbacks is if they appear spammy or the site linking to you is a site that you would not want your visitors to go to from yours (i.e. porn, warez, etc.). Or you might decide not to approve pingbacks for splogs and flogs (spam blogs and fake blogs), which usually are set up to borrow other people’s content and attract traffic solely through pingbacks.
Finally, I would seldom approve pingbacks from the bookmarking services. Why? Because those could be one way links. If you link back to them by approving the pingback then you are essentially cutting yourself off from one way links. Not generally a good plan. The only time you might consider approving those pingbacks is when you want your visitors to see a particular bookmark and vote it up so that it increases your chances to rank well with popular votes. Even then, my experience has been most site visitors won’t bother so I’d rather delete the pingback.
In the end, the decision is all yours. Establish a pingback policy so everyone on your staff will know when to approve pingbacks and when to delete them.