Something that’s aimed at bored housewives/girlfriends who’ll then get all their bored housewives/girlfriends friends to play because they need lots of friends to get anywhere on it, then they’ll drag in their husbands/boyfriends/parents/children. Then sell rare items in it that are a few pixels in size for far too much money like Gaia Online does.
(Edit: I’m serious about this by the way; cow clicker is the distilled core behind most of the successful facebook games out there, first intended as a parody but it soon became obvious it’s a very effective mechanic).
There would be many things to explain, but to make it short I would say :
Do your market researches before even developing anything. Know your audience, who they are, what they like, what are their hopes/fears/desires/dreams.
Don’t build something if no market has expressed a need for a solution. Ex : I need to show to the people that I am very clever and I can solve the hardest puzzle-games Ex2 : I need to show to the people that I contributed to help the people in Sendai by displaying a badge given by the Red Cross after I have confirmed my payment
Provide a solution to those needs and you will make money.
Focus on building something that people will want to talk about and share, and that makes them appear good to the others (in many ways, see below)
Find the tools that your audience use the most to encourage them to share (facebook, twitter, blogs, forums, digg, stumbleupon, many others)
It’s all about them. Make the people shine.
Social networks and social games are all about giving the user the ability to display his values and habits (strength/cleverness/happiness/likeability/cuteness/silliness/coolness/openness/whatever he wants to express) to the others in order to find his place and importance in a group.
Give them that tool that will help them find that place, and tell them how to climb (by playing more, by buying items, by destroying the others, by helping the others, by sharing more, by playing with cleverness, by being more ‘social’, by contributing more to the society ex sending the highest amount of money to the red cross etc etc etc). For you, the money is there.
You can apply that to any group that you target by, first of all, knowing what are the core values that drive them.
That would be the short answer. It works.
That’s (one of) the key(s) to facebook game marketing.
There would be a lot to say about monetization also. But my post is already too long.