Are you an expert on a particular subject? Offer people one free consultation via e-mail if, in exchange, they link to your site. This can be a huge draw, as consulting fees can be very expensive. Be sure to state in the offer, that the link to your site must already be placed before requesting a consultation. Have a form on the page for the user to fill out that includes the url to the link they have placed, along with their question and email address.