Most of us know the quote:
“Good artists copy, Great artists steal” - Steve Jobs
Copying and in extreme cases stealing is no news as a recipe for a successful businesses. Whether the term should be copy or innovation is not the issue here.
My question is why do sites such as Facebook, Google and Twitter who have quite a bunch of engineers at their disposal and we can assume they are very smart, bother to go through the process of acquiring rather than just "copying" or creating their own version of a application?
Most of this applications are made by a couple of programmers in a garage/basement and the application might not have a strong brand impact (yet), who of course are smart. When the "big" sites have hundred, if not thousands of programmers at their disposal and a strong brand and marketing impact.
Do the business mind on this companies with outstanding minds really don't mind offering millions/billions?
Note: I am aware that not all applications are acquired and most cases especially small features are plainly just copied.