You can use Google Adsense and Google Adwords. Advertising on GMail would cost you heavily.
they are negotiated
free
ALOT
Google blogs are free to use. If you wish to advertise on a blog you will have to pay for listings and click through amounts. If you want to use your Google blog to make money you can allow them to host relevant ads on the page.
its cheap
it cost about 5000 dollars.
It can cost pennies to thousands of dollars to advertise on the internet. It all has to do with how much money you would like to spend. If you use social media outlets, it can often be free.
I think it is about hundreds USD.
Nothing, If you have a valid reason why its free!
it would be around £15 to arounnd £30 to advertise something on a poster to make 50 posters.
100 million views cost 700,000 but i believe it has gone up.