Do you encourage your readers to opt in?

Do you have an opt-in? I don’t mean a “please subscribe to my newsletter” type of opt-in. I mean a IFO, or Irresistible Free Offer, that gets your readers to become your subscribers. I’m doing research for a telesummit client and I am amazed by the number of professionals out there with no opt-in at all, let alone an IFO.

So tell me, what do you have on your site and what are your thoughts about an irresistible free offer?