Sniper's high burst damage is useful in the early-game, while serving as okay damage towards the mid-game. Use it to pop high-HP Bloons, especially the Blooming Bloon. Notably, it can one-shot a Blooming Bloon except if buffed by the passives of Amelia's or Zee Jay. It has more overall ATK than most early-game Monkeys.
Compared to the Bomb Shooter, which costs 1 less Gold and has Armor Piercing, the Sniper has one less reload, has 10 extra ATK, and counts as a Military Monkey (mainly impactful for War Bonds).
While a decent candidate for Try this!, and serviceable in newbie decks, most other Monkeys are preferred for the early-game once unlocked. As a Common, however, the Sniper can be drawn more likely than more popular early-game cards such as Barrel of Monkeys.
Compared to Snipers of similar cost, specifically Leeching Shot Sniper and Night Vision Sniper, the basic Sniper has the highest damage-to-gold ratio but no utility or additional benefits.