[philthy]

"I think that social services that are public by default and have huge logged out user bases, should "phantom register" their logged out users by storing activity against their cookies and building user profiles on their logged out users."

What about if the user isn't allowing data to be stored, is using a vpn or proxy, a dynamic IP, or something else that prevents you from "storing activity"/comparing/etc.. I've seen this done before to target advertising to phantom users on adult sites, it doesn't work. Most of those people who aren't logging don't won't to log in/participate and "comparing activity" isn't exactly a piece of cake and is depending on those users having cooperating connections. You might argue that these people are fringe users but even then I doubt the ability/feasibility to accurately retain and compare data usefully and not just using IP or something to compare visits.

[edanm]

"You might argue that these people are fringe users but even then I doubt the ability/feasibility to accurately retain and compare data usefully and not just using IP or something to compare visits."

I'm not sure I follow you.

If a user isn't one of the "fringe" group which doesn't allow cookies, then you can store a cookie identifying the user to you, create a profile for them as if they are a regular user, and track anything you want. You can treat them like regular users, or treat them in a special way, but either way you can store any information you want.

[philthy]

Yeah you can store each sessions activity but how can you accurately compare the data between sessions?

[edanm]

You can put a cookie on the user's computer that isn't removed between "browser sessions". That's how most sites "keep you logged in", even after a browser restart.

What my framework (Django) does, and I assume this is simialr to other frameworks, is this: it creates a user object (see note) in the database, then keeps the user object id in a cookie on the user's computer. This is, by Django's default, kept on the user's computer for 2 weeks before being removed (and it can be made to never be removed).

Using this, you can store any information you want about a user in their user object in the database, and always have that information available to you via the cookie.

Note: by default, Django creates an "AnonymousUser" object for each visitor, not a real user object, and it is up to the site to create an actual user object. To implement that "PhantomProfile" that Fred Wilson is talking about, I usually make Django create a new user object with a temporary username, and use this instead of AnonymousUser objects. In this way, when they do decide to "register", I just keep the same user object and give it a new username.