It also depends where you lost it.

If you lost it at home, you are much less liable to get something, if you live in Canada and lost it in Australia where you were for 3 weeks and it never turned up, that is quite different.

I believe AC (all carriers?) have about 3-4 weeks to find it before it's considered permanently lost. After my experience (which including bag sitting in YYZ arrivals for almost 72 hours), I bought a Trakdot which has always been very good for knowing where my bag is. Except in Ottawa, oddly.