The freemium concept :

The freemium concept is a business model. It is running by offering basic services and the advanced services are paying. The idea is to transform the simple user of the service into a customer. Also, free added to premium gives freemium.
Text link:http://en.wikipedia.org/wiki/Freemium_business_model

we can find 2 online business utilizing freemium concept: skype, meetic, or flickr.

The advantages:

i think that this business allows customers to get free services.

Another advantage is that it will generate more and more customers.

The desavantages :

I think that the fact to get free at the first time and have to pay after will stop consumers to buy. They'll think: why i have to pay now?

Also, it exists some online users who are not feeling secure to pay online. They are asking themselves if it's a secure transaction.

And I think that customers will feel satisfied with a free online service. They won't need to pay for a service they got for free.

Easy group

Easy group is a business owned by Stelios Haji-Ioannou. It was created in 1995 and at the beginning it was easy jet. It has given many others franchises : easy pizza, easy cinema, easy hotel...

The easy business uses yield management. By that, customers can save money and time. It also pratices the low cost business and it permits to the company to be competitive with the other big industries. Because the customers prefer to buy in advance and they feel that the business is respecting them.

We can find many advantages to this company. For example, for easy jet, customers can reserve their seats at the last minute at a low cost. You can travel anywhere and the service has a good quality.