If that&#x27;s the argument, the writer needs to put up some numbers.<p>Here&#x27;s an attempt at some numerical estimates: <a href="http:&#x2F;&#x2F;www.bloomberg.com&#x2F;bw&#x2F;articles&#x2F;2014-03-03&#x2F;advertisings-century-of-flat-line-growth" rel="nofollow">http:&#x2F;&#x2F;www.bloomberg.com&#x2F;bw&#x2F;articles&#x2F;2014-03-03&#x2F;advertisings...</a>
Spoiler: ad spending in the US has grown roughly proportional with the growth of the economy, no bubble in sight.