Andreessen: Fab, a company in New York, has a lifetime value of people who sign up with Facebook that is twice that of people who sign up elsewhere.

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Facebook Messenger (for Android) in certain regions now allows people with no Facebook account to sign up for the service with just a name and phone number, without any Facebook account.

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Anyone can sign up for Facebook and interact with the people they know in a trusted environment.

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The company released a stand-alone messaging app in late 2011 and only started allowing people to sign up for a Facebook messenger account with their phone number last year.

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Spotify recently announced that new users must have an account with Facebook in order to sign up at all.

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Instead, users sign up by letting the sites access their Facebook credentials with one click.

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Practically, what this all means is that for the first time marketers can speak specifically to those users who they know something about and have already built a relationship with, either on Facebook or through a sign-up at a brick and mortar store, or an opt-in email program, or any other online or offline channel.

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Facebook has set up a link through that organization, where people can sign up with their state registries to become official donors.

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