1) A subscription box with which u can build an email list
2) An autoresponder which is embedded free of cost after much hardwork.
3) A rss subscription box, which will increase your feed readers.
The major reason why i m telling you this is that i m very happy because i created it for free and it is free to use and sites like aweber , etc that provides autoresponder, etc services for huge bucks are not needed any more.
You can hold any Giveaways, or u can create Contact, Feedback forms , etc with this method.
To know more contact me, and subscribe to my blog.