Uptown-Clean Crew is a company that provides house-cleaning services in major urban and suburban areas. Marketers at Uptown-Clean Crew developed a short, humorous video promoting the company's services and posted it online. Soon the video was a rage as customers who saw the video found it hilarious and they passed it on to their friends and colleagues calling it the "Uptown comedy." Which form of marketing is illustrated from this scenario?

Viral marketing

Explanation:

From the explanation of the scenario highlighted in the question, it is clear that Uptown - clean crew is using viral marketing to make its services known to potential customers and generates more sales.  

Viral marketing is a  marketing strategy  in which customers are encourage to share information about the product and services of a firm through the use of internet.  It is a techniques that uses the spread of messages (by users of the product ) to generate interest of potential customers thereby leading to a  potential increase in sales.  

two years ago, when picking flowers in the mountains back of yosemite valley, i found a book. it was blotted and storm-beaten; all of its outer pages were mealy and crumbly. the paper seemed to dissolve like the snow beneath which it had been buried, however; many of the inner pages were well preserved. and although all were more or less stained and torn, whole chapters were easily readable. this is the condition of the great open book of yosemite glaciers today; its granite pages have been torn and blurred by the same storms that wasted the castaway book.

two years ago, when picking flowers in the mountains back of yosemite valley; i found a book. it was blotted and storm-beaten, all of its outer pages were mealy and crumbly. the paper seemed to dissolve like the snow beneath which it had been buried, however, many of the inner pages were well preserved. and although all were more or less stained and torn; whole chapters were easily readable. this is the condition of the great open book of yosemite glaciers today, its granite pages have been torn and blurred by the same storms that wasted the castaway book.