I have a few domains without private registration. I often get an email a few months before they're due to expire from a business that will renew them. It's very strongly worded about how I'm about to "lose them", lots of capital letters and lots of red text. The cost to renew is $90 or so.

I've often wondered how many people fall for it (I assume enough they keep doing it), and whether they actually renew them, or just take some money and run.