Make money using mailing list

mailing list is an option supported by many web hosting companies, scripts and websites serving this service for free or for a little money as low as 1 $

by anyway make a mailing list

integrate it inside your website and ask your visitors to join you mailing list for recieving wahtever "newsletter-updates"
collect email addresses and you can use thim in one of the following two ways :

1- sell them to any advertising company .
2- use them for advertising for your own products or for your customers

How to make money on twitter for free?

twitter is a social networking service that is fastly growing
i think now one now dont have an account with twitter
ther are main two ways to make money with twitter
those ways are almost depend on how many followers you have

1- become affiliate on  twitter :
this a good way to make money on twitter
join a good affiliate program, advertise for whatever the product by posts ( tweets )

2- make money with revtwt :

this company offers ( cost per click ) CPC adverising
you apply for an account with it
they check your tweeter account and then accept your mempership
you place ads on your profile , and when some one clicks on an ad you get cash