To back this up with some facts:
https://blockchain.info/charts/estimated-transaction-volume?daysAverageString=30 <-- 30 day transaction volume on the block chain.
http://bitcoincharts.com/markets/ <-- there are 4(!) different active closed source centralized purely trust based exchanges that have several times that volume alone, not counting others and not counting the volume that comes from sending money to and from these exchanges. Also not counting brokers like Coinbase or BitPay.
Nice.
What is Ripple and how did it become so valuable. I am not to familiar with it.
I personally wouldn't concern myself with Ripple's "value" as it means very little in the near term. If you want to learn about Ripple though, I recommend you start with the Ripple primer. Enjoy.
https://ripple.com/ripple_primer.pdf