Using Jomclassifieds you can allow Vendors ( Advert Owners ) to promote their adverts.
Top ad 
It is the premium type where you can allow your vendors to post their advert at the top of a category.
- Login to your Joomla! back-end.
- Select "Components => Jom Classifieds => Premium => Edit [ Top Ad ]". Now you should see the following form.
|Name||Name of your promotion.|
|Description||Describe about your promotion.|
|Ad-LifeTime||Default value 1, is set. [Note: While posting an advert, users can choose number of days to promote an advert, within their advert lifetime.].|
|Price||Set price of your promotion.|
|Published||Select whether your promotion should be published or not.|
|Promotion class suffix||Optional CSS class added to each advert's container element of this promotion. You can use this option to customize the look of the adverts related to this promotion.|
- That's it. Save the form. You have successfully added a category to which the ads are going to be added in the future.You can also edit the above fields for both promotion and membership by using Edit option.