I have read recently, that Telegram won't hold a public ICO at all. They got all the money they need and will launch their token by the end of the year. I really believe, that the GRAM token will be a huge success.
Simply by the fact, that it will be the first decentralised messenger app and as we all know, Telegram is one of the prefered communication apps in cryto already and has a huge and loyal following. Compared to KIK messenger who failed gloriously with their KIN token, I see a huge potential with Telegram and I will for sure buy in. For me this is a no-brainer.