If you're a regular user of LinkedIn, surely you've invited people to join your network. Most likely, all of them have accepted your invite. However, if you've ever received the dreaded "I don't know this person" rejection, you should shape up before it's too late.
If you've gotten one of these notices, either you didn't really know the person you were inviting or you neglected to jog their memory about who you are. In all likelihood, it was an innocent mistake. Seems like a harmless error, right?
The short answer is no. LinkedIn considers this to be a big, black mark against you. Get five of these rejections and you have to start inserting an email address into each invitation to provide further evidence that you really know Sally Sassypants or Joe Jawannadance. If you behave from that point on, LinkedIn will eventually let you bypass this extra step. The catch is that you have sign an agreement that says you will allow your account to be suspended if you don't manage your network appropriately.
Ever get an email from someone you didn't know, but who asked you to send them your email address so they can connect with you (remember, people can contact you through LinkedIn without ever seeing your email addy)? Sounds fishy, huh? Well, chances are it's from someone who has been placed on LinkedIn's blacklist.
Those who know the damage that the "I don't know this person" button can cause, usually just archive requests from people they don't know. However, most people have no qualms about hitting this button if they don't know or recognize you. So, remember to use your invite privileges responsibly. Otherwise, LinkedIn might add you to its naughty list.