Snapchat is was the most popular app of 2014. So it might have the sum of 15 million. But Bitcoin is way more undervalued , keeping in mind that it's one of its kind. Startups tend to be overvalued since they always highlight their GMV , the Gross Merchandise Value, not the actual one.
More undervalued, you mean you think snapchat is undervalued at $15bil?
They will never make a decent profit, they will get lots of users and as soon as they try to monetize them, they will leave!
Whatsapp try to charge like $1 a year, and people still get annoyed! Who actually clicks these adverts enough that each user is worth $1000?