If you're more into the "real advertisement" idea, then you should try out any of the online classified sites. There are lots out there. You can publicize for free on all these sites though you'll be subject to varied limitations. You may upgrade your account so you get all the features you would like. Another intensely popular advertising methodology is pay-per-click ( pay per click ) which you can do on any of the major search engines. Again, here you pay what you want to pay.
Pay per click works in this way. Essentially, you may use these to find the precise terms that folk are typing in when they're seeking information on the web. Once you have some keywords, you'll create ads that are based around them. So, if your keyword is "internet advertising price", you may create an advert that contains that keyword in the ad and targets it so that when anyone types it in their search site, your ad will come up. Where your ad comes up depends upon how much you bid for your ad. If you do not have too much cash to spend, you may bid on the least expensive ( less searched for ) keywords. Even though it will take you more time to achieve results with these, the results will be centered and you won't be wasting your money on words that you cannot target competitively.