Facebook Throttling... What does that even mean? To the average Facebook user, not much. To a Facebook game developer, quite a bit.
Basically, Facebook Throttling has to due with the number of invites Facebook allows each user of an application to send out per day. The more invites Facebook allows, the more viral potential the game has. A game whose users can invite 20 friends a day is going to have a chance of spreading exponentially while a game whose users can only invite 3 friends a day is going to struggle.
So how does Facebook decide how many invites each game gets? Its science. Facebook keeps track of all of your game's social interactions. These interactions include invites, but they also include gift acceptance/request, sharing, etc. Facebook is interested in knowing the ratio of accepted interactions versus denied interactions. Therefore, if 1 out of 10 people accept an invite to your game you will have a low acceptance rate and then Facebook will "Throttle" your game and lower the number of invites players can send a day. However, there is a trick. Gifts sent to people already playing the game (such as your neighbors in 'whatever'-ville) also count towards your ratio. Players are much more likely to send gifts more often than invites AND they have a much greater chance of being accepted than invites. By integrated gifts heavily into a game, the developer is helping to insure their game has a positive ratio and therefore Facebook will increase the number of invites one can send out a day... or at least not Throttle it back.
I am not sure how I feel about Facebook's logic on this. On one hand they are promoting games that people are accepting and promoting. On the other hand, they are promoting games that spam people with gifts. Hmmm. There is an argument that its not spam since they are accepting it... but sometimes it can feel that way. The only compromise I can think of is to only use invites in determining their ratio. Ignore Gifts. Ignore Add requests. Ignore wall shares... etc.
We'll see if my opinions change once a get a few games under my belt.