IOTA is scalable in the sense that the more transactions are being made, the faster transactions will be confirmed.
But what I fail to understand (for any crypto-currency really) is that if every node needs to receive all transactions how will IOTA be able to scale beyond the number of transactions that can be handled by a single node?
Secondly if IOTA really becomes a backbone for the Internet of Things, won't the tangle grow so fast that you need to snapshot almost continuously?