By Josh Ong

Published: 01:30 AM EST (10:30 PM PST)

TapTapTap, the developer of the popular photography app "Camera+" for iPhone, revealed sales figures for the app on Tuesday, noting that just 5 percent of customers take advantage of the app's in-app purchases, while more than half the installed base updated to free upgrades within just 6 days of the update's release.

Tap Tap Tap head John Casasanta revealed the numbers in a post to the company's blog commemorating 2 million sales of the Camera+ application. Casasanta noted that reaching the second million in sales took just under three months.

"The one thing you learn to count on as an iPhone app developer is not to count on future sales based on past performance," he said, adding that "[the company's] fortune could change in a heartbeat."

Casasanta challenged reports that mobile apps are "quickly discarded" by using data showing that half of the purchasers of Camera+ upgraded to version 2.2 of the app within 6 days of the update's release.



He also cautioned developers from relying too heavily on income from in-app purchases. The $.99 "I (heart) Analog" effects pack included with Camera+ 2 sells to just 5 percent of purchasers on a given day. Casasanta admitted that a total of roughly $70,000 in income from the in-app purchase over a four and a half month period is "absolutely nothing to sneeze at," but also asserted that "it's very unlikely that this can be an effective business model."



Apple pulled the initial version of Camera+ from the App Store last year over violations to the company's developer agreement terms. The app contained a hidden 'easter egg' feature allowed users to remap the volume control buttons as shutter buttons.

TapTapTap had tried to include the feature officially, but Apple rejected it on the grounds that a volume shutter button could result in "user confusion." As a result, the developer included it as a hidden feature and revealing an activation URL via its official Twitter account. Apple promptly responded by removing the app from the App Store.

Four months later, the developer released an updated "Camera+ 2" with more than 50 new features, though the physical shutter button feature was noticeably absent.