not wanted: saggy couch.

So we have this couch, a craigslist find, that I like just fine.... its clean, leather-esq, and works well with our house. But its saggy. Super annoying. So we came up with a plan to fix it, that was FREE!!
-OSB board (that we happened to have laying around)
-cut to size.
-inserted.
-easy. done. not saggy.
-now I actually want to sit on our couch, because it doesnt swallow me up.
-its also very comfortable still, which I was wondering about.
-saves us about $600 for now...
-perfectly simple.