Of course you can do it, many ICOs are in similar situations in that they already have a working product or business. The only thing I would say is why does your project need the blockchain or a cryptocurrency? If it doesn't you might as well crowdsale somewhere else.
As well I can ask you why you do tokensale RIGHT NOW?
As I know, UT(in ypour signature) is a traders platform from Russia, who even made a hedgefund with name like "Kvadrat"(square is Russian), so why so successfull, knowing many investors and global markets professionals try to make ICO in blockchain?
Its not a question, hot money in the market!