Not enough foe variety in a zone forcing me to goto other zones. This costs me more than 5s as I need about three zones plus I need to WP back to my 80 zone. The reward is 5s plus a very tiny amount of experience. This might be nice for <80s but for us it is not something we go for, some days it just happens. Its not an achievement.
Suggestion
Scale the rewards better. Give something special like a exp booster or MF booster (getting these will entice people into your TP hungering for more. Not everyone knows they exist) or a rare gem or 5 peices of some random mat for crafting. Be more creative! Scale the exp reward to 1/5th a level to make it worth even shooting for. Give 10s to offset WP costs so we actually end up with ~5s ahead.