Promotion is a mix of Actions used to increase product/service sales through leads generation. 
It is one of the four elements (4 P’s) of Marketing (Product, Price, Placement, Promotion)
 

Objectives of Promotion
To present product/service information to consumers and others.
To increase demand.
Product differentiation.
 

It refers to the intensity (in terms of time, effort and spending) that each promotional type is being used

Types of promotion

Personal Selling. In-person sales, transactions made between sales representatives and clients.

Advertising.  Either audio, visual or printed. it employs an openly sponsored, nonpersonal message to promote or sell a product, service or idea.

Sales Promotion. It includes demand raising actions such as contests, coupons, freebies, loss leaders, point of purchase displays, premium  prizes, product samples, and rebates

Direct Marketing. Includes communication with customers through a variety of media e.g. cell phone text messaging, email, websites, online adverts, database marketing, fliers, catalogue distribution, promotional letters

Publicity. Refers to gaining public visibility or awareness for a product, service or your company via the media.

1. Target Market Determination 
2. Determination of Objectives 
3. Message Design 
4. Selection of Promotional Channels 
5. Budget Determination 
    

Example 1: Jeweller’s promotional mix based on a budget of 5,000 Euros

Example 2: Candy bar that fights tooth decay with 5.000 Euros budget

DOVE

Dove doubled profits from 1 to 2bn and turned the business of selling soap into a moral campaign.

How

Created a mock-up advert using all of the company directors' own daughters. With text alongside each image saying how these girls believed they weren’t beautiful, based on the existing images / models used in existing promotions, since their self-esteem was affected.  Promotion strategy changed with more “average” girl model type.

Nordstrom

A fashion retailer with $ 8,000 life-time spending per customer

How

Creating “Nordy Stories”, examples of great customer service from its employees. “Nordy Stories” give concrete examples to the employees to show them exactly how good customer service is given.
Example: A customer came into Nordstrom wishing to return a $17 tyre iron, without a receipt and in spite of the fact that the company doesn’t sell tyre irons the customer receives full refund. 
(They know that the Nordstrom customer has an average lifetime spend of $8,000. What’s $17 compared to that?)
 

GE

2 million views of Videos on Company Web-site after replacing heavy mission statements

How

The human brain processes visuals 50 times faster than text. Customers were attracted by the new appealing company presentation and used multichannel communication (YouTube etc) to spread the word!