You do realise $5 billion for a currency is, to use your term, shitcoin compared to conventional currencies which rank in the trillions of USD. That's not a target to hit, that's a minor stepping stone. Excellent progress for a 5 year old currency, but not by any means a destination. So, yes, any successful crytocurrency should be targeting substantially more than half the market cap of Snapchat (
http://online.wsj.com/articles/snapchat-fetches-10-billion-valuation-1409088794)
You do realize there are now over 600 crypto currencies and next year we'll have thousands, many with multi million dollar budgets and celebrity endorsements, while Doge has absolutely ZERO technological competitive advantages and is not even a secure coin (the very definition of a ShitCoin) which is the primary reason it has to merge mined with LTC and I predict that even with that addition of hash power it will still be hacked and forked cause it truly is an unsecured ShitCoin.
So then, looking at the big picture, it is a miracle for any such currency to reach $1 billion and the only reason doge may reach that is because it was launched and is secretly ran by a hedge fund, something I clearly stated multiple times last year. If that were not the case, doge right now would be valued at 1 litoshi.
Finally, comparing any ShitCoin, like doge, to the value of Bitcoin is delusional given all the money and power in the world is backing Bitcoin and the only reason these other currencies have any value at all is because of pure speculative reasons and due to a crowding out effect.