All free classified sites are not created equal. You should focus on a few good sites and post your ads regularly in those sites only. Your starting point is Google search. Go to google.com and search for "free classifieds" and "free ads". From the search result pages, visit 10 to 15 sites and register in those sites. If a site asks too many questions during the registration process, abandon the site and go to the next site. Why should you have to provide all your personal information for the site's benefits? Good sites will only ask minimal questions to setup your account so that you can edit, delete and renew your ads. Also, look for sites that will allow you to post without any registration.

Write a precise ad using 80 to 100 words. Write about benefits of your products and services for ad viewers. Try to think benefits in terms of generating extra income, improving health and relationships and providing a sense of good feelings when they use your products and services.

Write a concise, interest grabbing, key words filled ad title with action words that asks the reader to do something now. If you are promoting an affiliate product and many ads are also about the same affiliate product, write your ad title and ad copy differently than others so that your ad stands out in the crowd.

If you are selling personal items, like used cars, cameras etc., provide details description of the item, its selling price, and your contact information. If you are promoting an item to make a profit, do not try to sell your products or services in the classified ad. Use the free ad to lead to another site or your affiliate site where you can provide more information to make a sale.

In classified sites, most recent ads are listed on the top of the ad search or ad listing pages. Some free classified sites have paid premium ads which are displayed on the top of the listing pages, followed by the free ads. Avoid those free sites that accept premium listings. In free classified sites, your ads will be buried deep in the listing pages as more ads are posted in the same category. To keep your ads fresh and on the top of the listing page, renew your ads every couple of days.

Do not spam by posting your ads in all categories. Post only in a few relevant categories, preferably using different ad copies and ad titles. If the site has regional sections, e.g. US states, cities, or countries and your target is to reach every region, post in 10 to 15 regions only. For the search function of the site to pickup your ad for display, you do not have to post in all the available regions. This will save you time.

Always use photos or banners in your ads. Make sure that the size and dimensions of your image files are within the site's acceptable limits. Otherwise, the site may not display your images in your ad at all. There are a few free sites where you can create your banners or you can use your affiliate banners. If you are using the picture of a product, take the picture using a good digital camera and then convert the image to jpeg format and reduce the dimensions prior to uploading.

Using the simple techniques mentioned above, you should be able to minimize your online free advertising effort and increase responses from your ads. Remember, your ad title and ad copy should stand out with action words and pictures. You should regularly post your ads to keep them fresh and on top of the listing page.