Why is the significance of API testing ?

[Adrien007]

I liked the API testing tutorial . I need to tell my DEV to give me pre requisites to start API testing.
But what should I tell them why it is so important ? How I can bill the company for hours on soemthing that they never asked to me to spend on?<br> Please guide , as I always wanted to learn API testing and now when I know , how can I benefit it to the current organization?<br>Please excuse if you are thinking that I have learned a new type of testing but couldn't figure out why it is important.

Thanks

[softwaretestingforum]

let's discuss it in details. What do you think is advantage of using API in an application?

[Adrien007]

Its an interface between two applications. One  app can take advantage of another. We use google search API to show results via google on our websites search page w/o visiting google.