Peace be upon you
first of all, all written here is my own opinion and it mustn't be right all time :D,
someone send me and ask me to talk about "Using Web Service right."
this is issue !!!
really I mean it, a lot of people mess use it, Web service is amazing but over reacting with it cause a lot of problems to ur application, you have to use it wisely, you can make a 100% integratable system but you will also get a 100% unmaintainable system,
Web service has a lot of aspect that you have to care about when you are designing your system, and also you have to know that the decision of using the Web service must came in the architecture design level, before anything you have to decide that usage of your resources,
web service require more security + more Performance wise,
what I really like about web service is it's absolute control in your application against your customer, also you can do a great business by web service.
I will continue if I saw any comment :D, I will not keep writing to my self all time :D