What is the ruling on competitions held by some merchants on social media platforms, which require sharing the link to the store's page, where the winner is chosen randomly, and the aim is to increase followers rather than direct financial profit? And is there a permissible similar method for this?

There is no objection to competition prizes that do not impose financial costs on the contestant for sharing the link, provided that the store's activity is legitimate and free from deceit and fraud. However, if it involves deceit or fraud, participation is not permissible, based on the Almighty's saying: "And do not cooperate in sin and aggression."