Go
here to see the company builletin, where I update the best routes everytime they come out (every Monday and Thursday at 1am EST). I kinda messed up a lot this week but usually it's a lot better.
Here it says that yes, a lot of places want glass and Jacksonville is the only place to get it, but the distance between Jacksonville and the closest place that wants it (Detroit) is so far, that it makes the price per mile around $1.05 per mile, but if you go to the next highest demand product, Beer from St. Louis to Charlotte will net you at least $1.14 per mile. The 5 highest in-demand products carry a bonus of $100-$500.
Also, never take general merchandise, it pays $0.10 less per mile than everything else.