I highly doubt 50% of Facebook users will hop onboard within 1 year. Majority of Facebook users (in my experience) are old grandmas wanting to reconnect with old high school friends, or other elderly family members. Most of them probably can't work a smartphone, much less how to handle private keys, tx fees, addresses and so on.

Even then, if they could, I don't see it happening within 1 year. We just had a massive bull run, and now the hype is gone, and many people don't see it coming back any time soon.

I know it's used as an anti-spam measure, as are tx fees. ;)

It's all good dude. It did, a bit. Cryptocurrency is still new and in its early stages, so seeing 1 billion people use it within 1 year just doesn't seem possible to me. In my opinion, and in Satoshi's opinion, it needs to grow gradually. That's why blocks went from a few dozen/several dozen KBs, to a few hundred KBs, to 1 MB. That's why I was questioning why not go from 4 MB to 8 MB (as it did) to say... 12 MB, then 16 MB, and so on.