how google makes money through orkut?

That's a question best answered by Google reps themselves.

Google makes enough money through its targeted ad programs featured on google search indexes, Gmail inboxes and host websites that it can afford to offer a few freebies (like Orkut, for example) to keep Netizens happy and thus further boost its popularity. That's my guess and Google's policies does reflect a sound business acumen where it's a win-win situation for both Google as well as its user base.

though Orkut was free from ads, these days some sponsored links do appear on certain communities.
Once Orkut is more popular we will probably see ads & sponsored links more predominantly.

Advts mainly I thinks.

Ad now started appearing in orkut

Google must be making money somehow from orkut, coz the creator of orkut gets a few cents and dollars for each scrap or new profile or invite and so on.
Can't figure out how though.

I m seeing ads in orkut right from time I joined it that is around 3 months back.

Hey man did you see the sponsored links in Orkut. Thats how it's makes money.

NOthing new , social networking sites sell your information to the other companies which use the info for the targeted ads or offers. for example the communities you have joined on orkut show your area of interest or field of work.