Background Information
It's important to understand the limits that AWS imposes on its users in terms of the maximum number of instances, volumes, and IP addresses so that you can design your deployment accordingly and make requests for increased limits when necessary. For example, you might have received a This account has exceeded the maximum number of allowed instances
error message.
Answer
Although it may seem as though Amazon has an unlimited pool of web resources that it can allocate to its users at any time, Amazon does impose several resource limitations for each account in order to help safeguard against inappropriate usage. However, these limitation can be increased if you make formal requests to Amazon.
See Increase my AWS limits (EC2, EBS, ELB, EIP, E-mail) for a list of current resource limitations and links to the appropriate request forms.