With the Full membership you can activate the Invisible Mode. This mode allows you to view other profiles, without him/her receiving a notification about this. So your profile is still active and all other members can see your profile, it's just that they don't see that you have looked at their profile :) You can find the Invisible Mode under your Preferences.
Additionally, it is possible to "Hide" your account under your personal settings. When your account is hidden, your profile is not visible in any way for other members. Your profile information will be saved and can be re-activated whenever you feel like it. You can also find this under your Preferences.