What's better?

Recent research shows that making valuable content freely available is most effective. That doesn't negate offering additional content in exchange for an email address.

We're having this same discussion, but I have to believe we can be more successful if we know who our customers are (signups). We plan to deliver additional value in exchange for the signup.

I think if people cannot see why they should sign up, they will churn more likely. Either you can make a good promise (and keep it) or they may test it previously by getting free access. If you can provide content without signup and reserve some features that really add up value (e.g. read offline etc) for signed up users, you can reduce your funnel length and increase thrust. Theoretically, you can then convert the user at a later time to sign up (because of the advantages signed up users get). We drove some small tests with ~200 users and made good experiences with that (the "big" test is just about to come, though..)

I think it is always a good idea to make some of your basic content available to users to not scare them of at the beginning. If they wont register / login at first, they probably wont do it later. Also, it might be easier to skip the login during early development phases of your product and implement to login for additional content later. This way, you could release your product and get feedback for it earlier :)

This question depends a lot on what success metrics you're trying to make a difference on. What is your primary goal for the site? Some context into what you're working on would help. Secondly, requiring someone to signup for an account causes friction in their experience. Friction causes frustrations, so your goal should be to always reduce or eliminate friction whenever possible, even if you need them to signup for a full account. Like others have already said, if you're asking someone to signup, you need to provide value. Assuming here you're doing a pure content site/app, I'd suggest: 1) Skip any requirements for a signup initially 2) Start building up quality content and gain an initial following 3) Later on start asking for just an email address to help bring users back. I wouldn't block users from reading content, but would certainly make it very visible at the end of their viewing experience. 4) Only when I want them to gain access to exclusive content or some useful paid product would I ask them to complete a full signup.