Links and Images on Twitter won't count against 140 characters.

[Brian Altenhofel]

Still doesn't have to do with plug-ins reaching the limit.

For applications, keep track of tokens used by the application and invalidate those that haven't been used more than X times in Y weeks. There's a reason why it is part of the API. When you get to 50K tokens, request to be approved for 1M. When you get to 500-800K depending on your velocity, start making arrangements for a higher limit.

Twitter isn't just trying to keep users on their platform - they are also trying to ensure that the capacity and infrastructure is available for other applications to provide access to their platform.

[ArJol]

So what does it mean, that you can do however long tweets as you want as long as they only contain links and images