Drawing cards is often an endeavor rewarding in itself. It becomes especially beneficial with Chasm Skulker and
Lorescale Coatl
in the mix.
14 cards in the deck are 'unconditional' card draws, and 5 cards can, if certain conditions are met, also draw cards.
Example - if you have a Chasm Skulker or
Lorescale Coatl
out with at least one +1/+1 counter, Zameck Guildmage suddenly has: "UG: Draw a card". The counter you spend, you get back from the card draw. (Furthermore, if you have two such creatures out, Zameck Guildmage basically has: "UG: Draw a card and put a +1/+1 counter on target creature", since you net one +1/+1 counter. (Or two, if you have three such creatures out, etc.)
Snake Umbra protects an enchanted critter with totem armor, and draws if you deal damage to your opponent with that creature.
Spreading Seas is at worst a sorcery speed cantrip for 2. At its best, it will win you the game (if you for instance enchant an Urza's Tower at the right time). Often enough, it will disrupt your opponents mana base, net you one or a couple of +1/+1 counters, and draw you a card. Playing three of these motivates at least one Cold-Eyed Selkie, and they make the tokens potentially generated by Chasm Skulker when it dies much better.
Manamorphose helps you mana-fix, Gitaxian Probe lets you peek at your opponents hand - but mainly they're 0 mana cantrips (not quite, but almost) that pimp your creatures while drawing.
Birds of Paradise help you get a Chasm Skulker or Lorescale Coatl out on turn three.
21 lands are motivated by the high amount of cantrips, and the low mana curve. Sometimes, mulligan decisions will be difficult - but it's not a rare feat in this deck to actually overload Cyclonic Rift for the win.