Value proposition is a very important part of branding.
Value proposition is the tagline or the catchphrase that is an essential part of the marketing strategy of that particular product.
Value proposition should be such that it clearly associates with the values of the product or the service offered.
It should not be a random phrase that has nothing to do with what the product's worth.
It should be terse and expressive.
Less is more when it comes to value proposition.'
The catchline should be very attractive to the customers.
It should be easy to read and easy to pronounce so that the mass understands and connects with it

The value proposition is extremely important, it should be designed in such a way that it grabs the customer's attention and it should give the customers a clear idea about the value that your product is delivering. The value proposition is more than just a tagline or a catchphrase. A good value proposition should be clear about what the product is offering to the customers, it should also inform customers about how your company's product is different, or better from your competitor's.

Value proposition is not just about the catchy tagline. It may attract customers but what if fails to deliver. Value proposition is a promise of value to be delivered and makes it the main reason to be bought.

ex-
Kingfisher Airlines- Used to give world class facilities at economy rates.

Value proposition is nothing but what the product or service offers summarized in a line or two.
In a common man's word, value proposition is the catchphrase or the tagline as they say
For example: Mc Donalds: I'M LOVING IT
SONY: MAKE.BELIEVE.
Value proposition is extremely important for promotional purposes.
People identify your brand with your tagline
A good catchphrase is simple and easy to understand.
Value proposition is a potent weapon for positioning your product.
So, as marketers we should be extremely careful while choosing our value proposition.