We are building an app and I'd like to have a faster sign up process for users. Right now users can only get access after they got an invite by mail. After they got the mail, they can click on a link and they will be lead to the sign up form. This is asking for name, title and password. Next to the sign up form is a short text, what our app is about. After they signed up, they will be lead to the dashboard and have a 5 step guide, which explains most important functions and they are asked to do their first action.
Now I'm thinking about, how to get rid of the sign up in all these steps. The invite is necessary. So after invite they get a mail. The mail can contain:
1) a default password
2) a user specific login link
3) a link to the app
1) If they get a default password, they could login directly and start the walkthrough. Later they could update their profile at their profile page.
2) With the login link, they wouldn't need a password and would always be logged in automatically, when they use the link. Passwords wouldn't be needed.
3) They could get direct access to the app and do the walkthrough and after they did their first action, they will be asked to set a password.
Now my question: Which way do you think is best? Solution 1) is quite standard, they could login directly, but they would have to remember the default password or change it afterwards. I'm still not quite sure if solution 2) is safe enough and they would also have to save the link somewhere, so I'm tending to say that it's not quite useful, but it still came up as idea. Solution 3) would have the benefit, that they could use the app directly before finally signing up.
I really appreciate your answers. Thank you.