Instagram recently released web profiles for all users. Of course, your Twitter stream has probably been full of people linking to theirs recently*. Oh, here is mine. You may have seen so many people mention their Instagram web profile that you're sick of it.
But don't underestimate the importance of this feature to Instagram's growth. Think about how many times you've seen people say, on Twitter or Facebook or their blogs, "Follow me on Instagram, I'm cdevroe." Celebrities, with tens of millions of Twitter followers, had to ask their audience to launch Instagram, go to the search users pane, and type in their usernames there. And some usernames aren't so typing friendly. Obviously some did that, but some didn't.
Now, though, anyone can link to their Instagram profile. And rather than only a small percentage of people from Twitter following them on Instagram they will probably get a much larger portion of their audience to do so. This is big.And it isn't just about follows either. People can like and comment on photos from these profiles too. So interactivity on Instagram is skyrocketing.
I think Instagram's growth rate will increase with these web profiles in place.
* Instagram, like many other wildly popular social networks, released this new feature to all users over the course of about a week. There are many reasons for doing this not the least of which is the computational power you'd need to generate 100 million web profiles. However, I also see this as a sly way of having your users trumpet a new feature for you. It is free marketing. If everyone got their shiny new web profiles on the same day Instagram would have gotten one days worth of press about it. By releasing them over the course of a week they got a full week's worth.