Mass DMs are more effective if you want to sell a service or product directly to your audience. They’re great for lead generation because they help you explain what you’re offering more clearly.
Mass Mentions are better for boosting engagement on a specific post (like giveaways). They work well since one action can result in four to seven mentions, while Mass DMs only send one message per action (unless you're creating group chats).
If you're looking for growth and targeted traffic to your pages, InstaInfantry Pyramid or M/S is the best choice.