Start up a wordpress blog, write a content rich post that relates to your free service you want to market, spin the link as being a resource for the user as it relates to the content and use social bookmarking such as propelor, stumble etc. and send each of the top submitters a link to the post telling them what a great read it is blah blah blah...and have them vote for the post...soon you'll be on the front page and incomes the page views, clicks and conversions...might take some work, but I guarantee you it can work...not the best way, but def a way