By 2003, the idea had spread to almost 30 cities in four countries.
From the late 15th century the ideas spread around Europe.
And that's why the idea is, of course, spreading around the industry slowly.
The idea caught on and eventually spread around the country.
The idea lives a very long time and spreads slowly.
In mid-20th century, social scientists began to study how and why ideas spread from one person or culture to another.
Someone had a bright idea, and good ideas always spread.
Their ideas spread much faster and further than they did.
In the 1820s the idea of creating a national union was spreading.
The idea then spread to include the Democrats as well.