[simongr3dal]

Just a few idea: Make it useful to have a persistent identity, so you have something to lose if you abandon the account (like a library of games in steam, or a network of friends on facebook). Require a payment method and limit how many free trials can be activated with the same card. Require a phone number since they a harder to get than emails.

[karussell]

I really dislike services that require payment or telephone numbers for verification just to try out a service. And we are unsure if this increases friction for normal users.

[majewsky]

If someone wants to use disposable email addresses out of fear of having the service sell or abuse their permanent email address, they will most likely also not be willing to reveal their phone number.