If I see a promo that piques my interest I will check it out. If it passes the muster I will sub to it, but this doesn't necessarily mean that I will start reading it immediately. If it is a well established series with, say, fifty or sixty episodes already up, I will leave it until I have time to binge it. If there are only a few episodes I will catch myself up immediately. In both cases, once I am caught up I will continue to read the updates as they come.
If I sub to a series and it falls under the first scenario (where I need to binge it) I will often binge several episodes, say, a half dozen, at a time. Each time the series updates and it shows up in my notifications I will binge a few more, until I am caught up. If the series doesn't update I will usually simply forget about it.