It was more than two years, and it included 3 holiday seasons as well as multiple different game releases which cost ~$75 for the starter packs.  Amiibo won't come close to $1 billion in revenue this year.

It's own sales from last year. Wii-U did just over half in Smash launchweek of what it did in the same week last year.

Wii U is dead.. and it doesn't even seem like Nintendo cares enough to do anything about it.

Well they are releasing good games for it. At this point I'm not sure what else can be done. 

Home console is on a huge decline in Japan and now Nintendo is actually making big profits with the Amiibos and Wii U sales

If they make 3 million figures initally and still have shortages then they've still beat 770k. 770k is a tiny number to be throwing around IMO.