Hosting on Google Drive Edit
You may host your avatars and worlds on Google Drive which offers the fastest bandwidth for most users, enabling large worlds and avatars to download in seconds. Often bandwidth is twice as fast or more than Dropbox. Google Drive is free and only requires a Google or Gmail account. http://www.google.com/drive
Upload your file to Google Drive by dragging your file onto the browser window.
Right click the file and select 'Share...'.
Under 'who has access' select 'change'
Select 'On - Public on the web'
Copy the 'Link to share' URL
Convert the URL to a format usable by VRChat here: http://mrut.me/vrchat
Go into VRChat and paste the generated direct link URL into the custom field for the world/avatar.