why Google is offering so many freebies ?

i wonder why Google is offering so many free services and softwares....
staring with gmail some time back .. they have picasa- one of the best pic manager, calender, gtalk google notebook to name a few. theya hav also bought up some interesting looking companies.. skype is one, then they have orcut, writely ... the list is quite interesting..
are they buying any new company with good ideas. I think no.

The search related reserach community may have good guess at it. there is something called user model which help the search engine in retriving relevent results to the user. At present no search engines use user model. building a good user model is still a open problem. But the way google is collecting users information it will not be long that we will be able to get a personalized search engine. which knows users friends, his schedule, his past emails, chats, future plans, contacts, his documents and much more....

still a question remains unanswered to me .. is it always the case that what we expect from our search really depends on our deeds ;)