Attention can make us feel acknowledged, appreciated, and valued. As a result, a lot of people seek attention.
In general, if one wants attention, he/she will do something to try to get others to notice them. This can include: posting a lot of pictures, messaging a lot, doing something out of the ordinary, being very loud, making controversial statements, and so on.
Some try extremely hard to get the attention of others. This may be because they feel that it validates their existence. For example, for devoted fans, it means the world to them if their celebrity crushes notice them. Thus, it is very common for extreme fans to continuously bombard their celebrities with tweets and comments. To them, if the celebrity ever responds or retweets to even one message, they feel like it’s all worth it.