Do you see those empty billboards along the highways?
We've noticed quite a few of them in recent months: blank billboards; one after another along major roads.
These billboards have no visible message but they convey a powerful message nonetheless: The economy is not recovering. Businesses are still cutting back. Advertising is down because business is down. There's less to advertise (fewer businesses) and there's less to advertise (less money to spend on advertising).
When you stop seeing blank billboards along the highways then you'll know that things are beginning to pick up again.
Until then, you don't need a degree in economics to figure this out: The stimulus ain't workin.