The brand's ability to keep pushing the creative boundaries has also come into question. Instagram's original team of four - including founders Kevin Systrom and Mike Krieger - has maintained a lean operation, despite the brand's explosive growth over the past year, with little more than a dozen employees working from Twitter's old offices in San Francisco at the time of the acquisition. This has given the brand a reputation for being nimble and creative.
In light of Facebook's acquisition and the backlash of its vocal core user base, how can Instagram ensure that it continues to appeal to its fans and stay true to its values?
We asked former Photobox head of acquisitions and partnerships Romain Bertrand, who is now head of marketing at fundraising website JustGiving.com, and Daniel Rosen, the former managing director of mobile at AKQA, now chief executive, EMEA of WPP-owned mobile marketing agency Joule.
Many questions have been raised about Facebook's reasons for buying Instagram. Is it simply acquiring a lot of data, and a vibrant, loyal and fast-growing community of 30m users that doubled in size in the past five months? Will it try to capitalise on its $1bn investment too quickly, and become another social-network killer? Can Instagram give Facebook a soul, or will Facebook destroy the soul of Instagram?
Some are clearly sceptical of Facebook's claimed intention of remaining hands-off. Instagram has a (very) small team of only 13 people. Should the Instagram founders go on to leading Facebook's mobile efforts, for example, Instagram could lose its way quickly.
On the other hand, the potential benefits are huge: investment will help improve features and grow the user base - Facebook knows about scaling.
It is too early to pass judgement, and fears of a customer exodus, for now, appear greatly exaggerated. It is Facebook's first big acquisition after all.