A perfect example was a comment left in an entry form from my contest. There are several different types to choose from, from the simple entry drawing to the more challenging trivia contest. The simple drawing is probably the most popular because it requires the least amount of work on the contest entrant's part. The only thing required is their name and email address. Deciding which type of contest to run will rely on how much time you will have to dedicate to the entries that come in.
Drawings require virtually no effort.
All entries can be filed until you are ready to draw a winner. You've decided that running a contest will be beneficial to you. You may have to fund the first two or three contests that you hold on your site yourself. Or if you own a retail site obviously you can offer a gift certificate or specific product from your own shop. It doesn't matter.