Hm; to me personally, one advantage is that I immediately understand the idea and usage method of their service, while reading the links you provided I can't grasp what they're trying to communicate, unfortunately.

Also, I know Lua and value it very highly, so seeing it mentioned immediately focused my attention.

Thirdly, "free" "unlimited" "renewable 7-day" trial sounds great, and $5/month for persistent does too.