How did facebook apps reverse the install dynamic?
The hot new thing of the web of late has been facebook apps. I must admit Facebook itself has been great for me at finding old friends because for unknown reasons, almost 20% of Canada is on Facebook compared to 5% of the USA. Facebook lets 3rd parties write apps, which users can "install" and after installing them, the apps get access to the user's data (friend list) and can insert items into the user's "feed" (which all their friends see) and sometimes send E-mails to friends.
I haven't examined the API enough to understand the reason, but there are many Facebook apps that are very, very annoying in how they operate. Most won't let you get anything from them unless you "install" them and give them access to a lot of your data. (There are a few that let you have more limited temporary use through a login.)
This is annoying because you constantly get data in feeds (or emails) which is just a teaser. "Fred Smith wrote something on your pixie wall." You have to follow the link, and find you must install the application before it will show you what the other person wrote. It could easily have shown you the text in the feed or email, but it doesn't want to do that, it wants to spread virally.
But this is far beyond viral. Viral apps usually work because friends recommend them. These apps push to install just because a friend used the app in reference to you.
Outside of facebook there was a different dynamic. Usually if you used a social app which emailed your friends, your friends could do their part just on the web site, without creating an account, or providing personal data, or "installing" something. (The install on facebook isn't like a PC software install, but given the data it gets access too, it is pretty insidious, a form of super-spyware.)
There were a few apps which required your contacts to create accounts and enter data. They got a lot of pushback, and this largely stopped. Most of the apps certainly encouraged your friends to create accounts, but few forced it or sent a message that was useless unless they did create one. (Not counting deliberate invitations to join a system which obviously work this way, and which you tend to send one-by-one, or so most companies learned.) As much as I hate evite they still let the people you invite RSVP without doing any account creation.
In facebook it's the reverse. One app I tired and hated asked questions. It ended up putting text into the feed and emails of the form, "Joe has asked a question, click here to see what it is" and "Mary has answered Joe's question, click here to read the answer" instead of putting these short text questions and answers right into the email. And answering a question required installing the app.
I see a few things that have driven it this way. First of all, when you install a Facebook app, it informs all your friends in the feed. That's publicity for the app. And they get to increase their total number of installed users, which gives them more visibility when people look to see what's popular. If the app let your friends get data without making them join, it would not have so many users.
Apps are not forced to do this. A number of good apps will let people see the data, even put it in feeds, without you having to "install" and thus give up all your privacy to the app. What I wish is that more of us had pushed back against the bad ones. Frankly, even if you don't care about privacy, this approach results in lots of spam which is trying to get you to install apps. Everybody thinks having an app with lots of users is going to mean bucks down the road, with Facebook valued as highly as it is.
But a lot of it is plain old spam, but we're tolerating it because it's on Facebook. (Which itself is no champion. They have an extremely annoying email system which sends you an e-mail saying, "You got a message on facebook, click to read it" rather than just including the text of the message. To counter this, there is an "E-mail me instead" application which tries to make it easier for people to use real E-mail. And I recently saw one friend add the text "Use E-mail not facebook message" in her profile picture.)