Can someone explain Map rewards
It is not displayed in-game nearly as well as it should be, but here’s how it works.
The Map Rewards system is a reward track like PvP Reward Tracks. Each map has eight different tracks, which rotate weekly (Thursday is the rotation day). Earning 200 points on the unseen progress bar gives you a reward, with bigger rewards at 4000 and 8000 points. Each event you complete gives you between 110-120 points towards a reward, meaning that you’ll always get a reward after completing two events, and sometimes get back to back rewards from events due to the overflow.
http://wiki.guildwars2.com/wiki/Map_bonus_reward
Clicking links on that page will give you the full reward lists for the maps. Map rewards give you a way to concretely progress towards certain goals, like Silver Doubloons or Vials of Powerful Blood.
You can also progress a Map Reward track by doing jumping puzzles or mini-dungeons in zones. You’ll get credit for those once per day per character, with an event popup on reaching the end chest.