Stickies at the top of the list are chosen at random and are changed at random. An ad that is submitted months in advance of an event may be sticky for awhile, removed, and become sticky again at a later date.
There is a good chance that your ad will be made sticky at the top of the list for a period of time if some of the following are included:
The title includes the date of the event. (It is not necessary to use title space to include the location as the location appears in the green line below the title. )
The ad is urgent or includes a specified time frame for sale or pick-up.
A small donation is included to help defray the expense of developing and maintaining the Briar Press site, especially if the ad is generating income for a service or event.