In fact, this happens quite a lot these days. Someone uploads their contact list to their social networking account, and voila. Since we have set our e-mail program to remember everyone we ever send mail to, most of us have a fair number of contacts who, for the life of us, we cannot remember. Perhaps we answered their question on a professional mailing list. Perhaps they recommended a plumber to us. Perhaps we did business with them a decade ago. Maybe we met them on a bicycle ride.
Personally, I have a lot of business contacts I can't recall, because I worked as a consultant for almost a decade, and have been a prominent contributer on a wide number of listservs, as well as a moderator for a few. Because I was a consultant, I made sure to upload most of the business cards I got, and use LinkedIn to connect to anyone I ever did work for or who did work for me. (If you are a marketing consultant and don't have many contacts on LinkedIn, you don't look like much of a marketeer.)
Also, as a marketing person, and just as a friendly type of person, I tend to "friend first, ditch later" rather than "ask first, friend later". I've ditched very few friends. As long as someone isn't sending me some new app twice a day, being lewd, or trying to sell me stuff, they are my friend. You are my friend if you are reading this, as far as I am concerned. I never complain about having too many friends.
But it did occur to me, as my newfound friend and I were both denying First Friending rights, that for some apps, false friending could be a feature rather than a bug. For example, a dating application could set up an algorithm that would take into account age and geography, and set you up with a match arbitrarily.
Obviously, if they did this too often or too blatently, it wouldn't work. But if 10% of the matches you got were faked by the system, you might never find out and it might increase your satisfaction with the app. At first, as a marketer, I thought: what a great idea! Forget the ethics of it, you can always justify giving people more friends as morally good. You can get people to use your system more by making them artificially popular!
In fact, none of us really know how Facebook apps work at the backend, and we are astonishingly nonchalant about adding them. The apps have access to our personal data, and we usually have no idea who the creator is. (I have one developed by my brother-in-law, but that's an exception.)
And for all we know, they are sending us fake flirts, fake greetings, etc., from our real or virtual friends. Did you really challenge my knowledge of '80s sitcoms? Because most of my aquaintances are aware that neither my current home nor my childhood home had a television set.
In short, we don't really know what any of the applications are doing. We don't really know if the notifications are real or fake. Marketers may think they are very clever by creating defaults that make it seem our friends are constantly sending us something, inviting us, or challenging us. Frankly, it's only clever for about a month. After that, it's just noise.