You have some really good hubs but you are still new (4 months). It takes time to see significant results. I have less hubs than you but have seen my traffic rising of late. Apart from writing hubs on a regular basis try to comment on hubs of other people and answer questions in forum. Another great way to increase traffic and revenue is to take part in contests like Hubmob weekly contest or the 30 day 30 hub contest. All the best.
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