The following tips help you reduce the possibilities of being rate limited:
Caching
Cache responses on your site, so that when your users requests for the same data, you load the stored response instead of sending another request to the ei API.
Spread out requests
Do not make too many requests at once; instead, spread them out over a few seconds.
Priotize your requests
For example, you may want to priotize the requests of your premium users over that of your free users.
Reach out to us
If you are accessing the free API, you need to request higher rate limits.