I would say one of the most important aspects to consider is the workflow of being a 'demo user' to signing up. Sure, rewriting your app's sign up process into an 'online demo' by automatically generating a guest account won't take that much time. But the real challenge is to make sure you're designing the whole process in such a way that you're not adding more confusion for the user. For example - and this is probably more relevant for B2B/enterprise apps - users might be really used to having to sign up with a password (or even worse, having to fill out a Request for Demo form and wait for a call from a sales rep). In that case I'd try to make sure your users understand whether or not the data they enter is private or shared, if it's saved once they "sign up", etc.
We also notice that our users sometimes create an account, play around a bit, but then leave and come back again a few days later because they were in the middle of something. I'm curious what the effect is of having no way of contacting them, or leaving a reminder in their inbox of where to find back the website. Maybe just asking for an email address would help.
In any case it would be interesting to see some more data. So far we've just been using sign up forms, but always try to keep them short and 'friendly'. We're definitely considering giving this a try, so hopefully we have some meaningful data to show in a while.
We also notice that our users sometimes create an account, play around a bit, but then leave and come back again a few days later because they were in the middle of something. I'm curious what the effect is of having no way of contacting them, or leaving a reminder in their inbox of where to find back the website. Maybe just asking for an email address would help.
In any case it would be interesting to see some more data. So far we've just been using sign up forms, but always try to keep them short and 'friendly'. We're definitely considering giving this a try, so hopefully we have some meaningful data to show in a while.