Popups. We all hate them. But from a marketing perspective, they work.
Thing is, some work better than others.
And the other thing is, the ones that work well, while not annoying the fuc* out of people, tend to be a hassle to set up.
So to solve those problems, here are two popup services to check out. They are not annoying. They work well. They are easy to use. And even better, they are free (at least at the time of this writing):
and