The free iPhone app hit the App Store in early October, gaining an impressive 100,000 signups in its first week. Clearly, that trend has remained steady, as just 10 weeks after its debut, the app has passed the 1 million registered user mark.
Earlier this month, Instagram co-founder Kevin Systrom told us that the photo-sharing app was seeing two to three photo uploads per second.
Instagram's continued success is indicative of a much larger mobile photo sharing trend. As Mashable's Jennifer Van Grove wrote, "mobile photo sharing products from Picplz, Instagram and Path represent the next boom in photo sharing."
Thanks to a combination of ever-improving smartphone cameras and the ability to instantly share photographs to social networks like Twitter, Facebook and Foursquare, these photo sharing apps often provide the simplest way to share photos as soon as they are taken.
Instagram has been particularly proactive in adding features to its app, including support for more networks, more filters and more language translations. Inline support of Instagram-tweeted images has even been added to Twitter.com.
Keep in mind, Instagram is still an iPhone-only application. Unlike competing services like Picplz, Instagram doesn't offer the ability to browse or share photos outside the context of the app. To us, that makes that 1 million registered user mark even more impressive.
I know that on a personal level, I've started to use Instagram as my default photography app. Why? Because it's super fast and I can instantly share with my various social networks in one step. Moreover, I find myself spending more time looking at my friends' photos within the app, getting a better glimpse at what they are seeing and experiencing.
What do you think of Instagram and the overall trend of mobile photo sharing apps and services?