The development on additional features and improvements to your game should be driven by intelligence gathered against real users playing your game in market. We call this Milestone development against benchmarks.

Let's say your game has a retention profile that looks like this:

• 10% come back on the first day
• 5% come back on the seventh day
• and 1% come back on the thirtieth day

These numbers are sub par compared to industry benchmarks:

Depending on your game, it's primary audience, user type and platform, you will need to assess what metrics your are failing to hit benchmarks for and shape your development to hit them.

If retention is a problem for you game, here are some examples of solutions:

Make a quality product. (obviously the most important thing on this list).

Increasing difficulty. Make it easy to level up at the beginning of the game, and then make it increasingly harder and take longer. This will make the game more challenging. This is also a monetization technique because users will buy coins, etc. to speed up gameplay.

Mobile push notifications. Remind users to to log back into the game when you publish new content, or when they need to take an action (feed a pet, etc.).

Energy. If users need energy to keep going, they will either buy energy or wait and come back several times a day.

Provide deep content. Publish new themed content on a regular basis.

Seasonal content. Offer content specific to the season or holidays. For example, Tiny Zoo recently offered special animals for Father's Day and decorations for the Queen's Jubilee, and Zynga launched an entire new version of CityVille for the winter holidays.

Collection completion. Users will repeat actions to complete collections or gain a new skill.

Story development/Quest unlocks. Users are incentivized to engage in the game-or pay for coins/energy/gems-- to advance an interesting story/plot. Zynga is very weak in this area, but it's getting better.

Identity development. Users can develop a sense of identity through playing a game. An example is Vampire Wars, which was very attractive and engaging to young people interested in goth culture/fashion.

Build a hardcore community. You can do this with wikis, Facebook pages, and other social platforms, or more sophisticated custom solutions.

Offer shareable power. Players help other players. Tiny Zoo and Tiny Village both offer this with tips-- users can leave tips for other players after they visit others zoos/villages. You can see another example of shareable power in Mafia Wars-users can "save" a player/friend that's losing in a fight.

Care obligation/Tamagotchi (users will log in to take care of characters in the game). Tiny Zoo uses this technique with babies that must be placed in their pens before they get "sick," requiring users to log back into the game to take care of them. One of the earliest examples of Tamagotchi are those virtual pets on keychains sold by Bandai.

Announcements of new content in-game. At game launch, when leveling up, etc., announce the latest animals or content themes.

Daily rewards for returning. There is some argument about the effectiveness of daily rewards, so you may want to read up about this or run your own A/B test.

User Generated Content (UGC). A great engagement tool, both for content creators and content consumers.

User profiles. This allows users to develop a sense of identity in the game (more essential in social mobile games)-- it also generates a sense of investment in the game. The more sophisticated, the better.

Network effects (users are drawn to the product because their friends are already there). Truly social games like Draw Something rely on network effects to both attract and retain users.

Engagement loops with organic notifications from other users' actions. Forexample, receiving an email from Facebook when a friend posts a picture of you and tags you. The message from Facebook is something like "Your friend has posted a picture of you on Facebook." Even if you're not an active Facebook user, you will be compelled to log in. This essentially draws you into the network via your friends.

Stat boosts/ skill specialization (users buy or earn points that give them a specific kind of skill in the game). This was used in Mafia wars, where users could become specific kinds of mobsters with specific skills if they earned enough points. This is also a form of identity development.