Getting rid of the version of someone elses very good enchantment (why play Ghostly Prison when someone else will pay for it?), instant, or sorcery that we had to destroy and then getting our own version is good beats
For just 1 blue mana, it counters a noncreature spell unless your opponent pays 2, which is often a back-breaking tempo swing in the early game
How many haste-smashes will your creatures give you
Goldvein Pick is a strong starter, especially if you have some cheap evasive creatures to get in for damage
Because Electroduplicate gives your tokens Haste, you can swing in for infinite damage to end the game
Likewise, Smothering Tithe and Monologue Tax are superb Enchantments that help to ramp a white deck up, but if you dont have the cards to spend the Mana on, then youre still a sitting duck