Compounds that have the same molecular formula but different chemical structures are called isomers. Depending on what types of differences there are between the structures, it is possible to classify isomers into various sub-types.
The Limit. You can follow up to 7,500 users before receiving the aforementioned error. Instagram invoked this limit to reduce spam in their system and keep users in compliance of their Community Guidelines. However, some users can follow more than 7,500 users if they did so before Instagram imposed the limit. Some Instagram users also claim there's an hourly or daily limit to the number of new followers you can acquire, but Instagram has not confirmed such restrictions.
With Instagram Direct, you can reach your most engaged fans via a personal message. In fact, you have the option to reach out to individual followers or create a group message of up to 15 followers. You can even segment your group based on location and demographics. What an opportunity! To find your most engaged fans, look through your photo stream and see which followers stand out.