Frankly , slapping an ip-address to an existing application and pushing it behind a pay wall and selling a hundred such services as webservices and advertising extensively as a newly minted architecture called SOA by companies like IBM can carry away gullible people . But such focus-less short termed architectures damage the real intent behind a concept and mislead people.
Wasting a lot of time and money.
The real purpose of a service is far more involved and deep. Essentially, services were needed to remove the limitations surrounding application development. A few of the previous limitations overcome by services are as follows.
1. By removing the limits on the processing power available for an application , the scope of a program is greatly widened. Bigger, more intelligent and automated solutions are possible.
2. An application available as a pay per use service instead of an installable app is more affordable and the reach too is global.
3. One of the most important aspect not to be missed out is to understand that a service is essentially manipulating data. Such an understanding makes the service more global, your application remains the same only the input data is changing.
4. Also on removing the limitations on the amount of data one can build extensive and long lasting applications which are also intelligent.
That's just the tip of an iceberg !!!