It would be better, instead of creating "Snapster" to centralize the social. network?

Question

Computer networks

"vk.com" launches "Snapster", although in the social. networks can also upload photos, with the exception of filters and other lotions.
Wouldn't it be better for them to improve the "vk.com" application for snapshots than to create "Snapster"?
And why should Instagram users, as intended by the creators of Snapster, go to them?