Riot should seriously consider adding 4-Win XP boost for email verification.

I can give a long winded psychological reason behind this, but anyone who is smart at marketing would have already have done this. Go ahead and delete this right away.

TL;DR: People who get the 4 win boost will see the xtra xp, they will then lose that bonus after 4 wins and see they aren't getting as much, people who spend money to progress further would likely do so, increasing sales, without this, there is no incentive to purchase xp boosts.