The amount of traffic is an indicative limit. The amount of data traffic depends on the number of visitors, pages viewed and amount of media per page. For example: 5000 visitors viewing an average of 10 pages per visit would result in 100GB data traffic.
It's no problem if you rarely exceed this limit. We'll get in touch if the data traffic limit is exceeded occasionally to talk about a working solution.
Please contact us if you already know that you're going to distribute your interactive stories to a very large audience (ie. 25,000 recipients). We can facilitate additional caching layers and advise you further on the distribution of your story.