I'm monitoring a website where I have two kinds of users (say, A and B). These users are able to contribute to this site in a variety of ways and, for each contribution, its time is logged. What I want is to compare if the number of days that the user is active (contributing in some way) differ between the kinds of users.
I'm monitoring the website since it's beginning until four months ago. Not all users joined as soon as the site was created nor users that joined at the beginning are still contributing.
Is survival analysis suitable for this comparison ?