Spam works.But that doesn't mean everyone can do that with all the junk.People still do splogging, way to way sites,doors and cloaking sites as you seen everywhere those viagra,russian or warez.
But it must be optimized with ranking factors like ALTs, by placing authority links, images and a bunch of videos, etc. Content doesn't need to be readable, but it should be optimized.
Follow what your competitors do.(on page as well as off page)
After all it needs least 20 - 30 days to see results.
I can give some tips if you are PM me.