What do you do if you have a 3 Million Rand idea that you want to sell to Google?

I have done a little bit of research on this topic and I haven't come up with an answer yet. 

There seem to be a lot of developers out there who claim that getting a large company to buy your idea has similar odds to winning the lottery. I say that if you want to win the lottery, the first step is having a ticket. So if I want to sell my idea to Google, I have to at least put it out there. 

It seems as if Google have purposefully kept their contact details as private as possible because so many people out there believe they have the next big thing. If they advertised, they would be inundated with calls and emails and their servers would constantly be full, so how do they find out about new ideas. They would be silly to ignore the potential of the world of knowledge at their finger tips. What they do have is access to what everyone searches for and the sites that they visit. So by now I guess they know I have something I want them to consider. 

The next question is how do I get the idea across to them without giving away the idea completely. This is the problem with an idea, its just that until someone does something with it. There are also probably hundreds if not thousands of other people who have come up with similar ideas. What makes my idea better than theirs? I have looked a little into patenting and it seems as if its not really worth the money that would have to be spent on it to ensure that it is no-one else could reproduce it with just a few small changes.

I guess the guys at Google have to risk the fact that most ideas will already have been developed in some way or another... but what if my idea is in fact that one that is unique, or at least there is a feature that gives it enough of an advantage over whatever else is out there that could make it the next big thing. What if my idea could make the difference that would take Google+ and make it surpass any other social networking platform available?

The only way they could ever find out would be to find some or other post like this and read into the belief of its writer and contact him to ask about it, set up a meeting, get the details and enter into an agreement with him...

Am I living in a dream world?????

Lets see.