Silver and Bronze Medals

I have noticed that some tournaments award gold medals and some award gold, silver and bronze. 

What determines the number of metals that are assigned after the tournament is completed?   Some tourney's only give a gold for first place and some give medals for 2nd and 3rd place too.

I am directing a couple of tournaments that are about to start or have just started, I would like to have my tournaments to give metals for 1st, 2nd and 3rd place but I can't find a setting to allow this.  Does someone know how to do this?

Any help would be appreciated!

I think it has to do with # of participants

If a tournament has 8+ players, awards will be given to 1st, 2nd and 3rd. If the tournament has less than 8, only 1st will get the award.

Please take a look at http://www.chess.com/tournaments/help.html#winner for more information on this topic.

Thanks!