Dropbox is a Web-based file hosting service for Windows, Mac, Linux, iOS, Android, BlackBerry OS and Windows Phone.

In this instructable I will discribe the way you can maximize your Dropbox storage up to 20GB.

The first thing is to get an dropbox account. You can get 2.25 GB by using an referral link like this one : http://db.tt/3nTx6SQ4
Its my referral link an you can get 2.25 GB because I am student.
Register your account on the dropbox main site and you only get 2GB.

Step 1: Complete the Getting Started

After you signing up to Dropbox, You will get on the Getting Started page.

https://www.dropbox.com/gs will guide you to the Getting Started page.

Complete the following tasks to gain 250MB free space added to your Storage.

1.Take the Dropbox Tour
2.Install Dropbox on Your Computer
3.Put Files in your Dropbox Folder
4.Install Dropbox on Other Computers You Use
5.Share a Folder with Friends or Colleagues
6.Invite Some Friends to Join Dropbox
7.Install Dropbox on Your Mobile Device

Now you have collected 2.5GB of free storage

Step 2: Complete the Social Connect Page

The next step is to connect your social network with your dropbox.
https://www.dropbox.com/free is the link you have to use

The following are tasks to be completed in order to get upto 640MB of free space.

1. Connect your Twitter account to the Dropbox account.
2. Connect your Facebook account to the Dropbox account.
3. Follow Dropbox on Twitter.
4. Give feedback to dropbox as to why you love Dropbox. Write a line about Dropbox in the field.
5. Tweet about Dropbox on your Twitter account.

Don´t be afraid to connect your networks, dropbox won´t do any posts or something like this.
And you can delete this connections afterwards and save the space.

After this step your storage is 3.14 GB

Step 3: Beta Testing or Dropbox App

You can get up to 4.5GB by using the dropbox beta or App to upload pictures or movies.
( Download here: for Win http://dl-web.dropbox.com/u/17/Dropbox%201.3.21.exe or for Mac http://dl-web.dropbox.com/u/17/Dropbox%201.3.21.dmg)
Dropbox App is available vor IPhone, Andriod and Windows Phone at the Appstore.

Using the App you only have to apply the automatic upload of your Pictures and wait until they have been uploaded.

Using the beta:
1. Install the beta
2. Take any USB-Stick and create an folder called DCIM
3. Copy some pictures or movies to DCIM
4. Plug in your USB-Stick again and apply the automatic upload of the content in DCIM

For the first picture you get 500 MB and after Uploading 500 MB you get another 500MB and so on.

I used three 1.5 GB movies and cancelled each upload seperatly and get 1.5 GB for each started Upload.

After that you can delete all files in your dropbox.

Now you have 7.64 GB storage.

Step 4: Referral Method

You can earn up to 16 GB for inviting your friends to dropbox.
First access the .Edu Linking page https://www.dropbox.com/edu
If you are a student you can register you educational email address
Now you get 500 MB instead of 250 MB for each referral

Here are different opportunities to get 32 referrals to earn 16 GB
1. Invite real friends
2. Use VirtualMachine and Mac-address changer to create multiple dropbox-accounts
3. Use Google AdWords to advertise on google for a few dollars

Maybe I discribe the last 2 Methods later.

After 32 referrals you have collected 16 GB an your storage is now 23.64 GB