The numbers behind the disappearance of landlines

There are more indications that the days of landlines/POTS/plain-old-telephone-service are numbered, including these statistics from a article:

"Verizon's landline revenue has fallen 19% since 2007, and AT&T's is down 16.5% over same period."

And this, from the same article:

"Nearly 32% of American homes are now cell phone-only households -- double the rate from 2008 and nearly triple that of 2007, according to a recent government study."

It's not a surprise in this industry at all. How many of your new alarm system installs are communicating over cellular, proprietary wireless, or IP?