pbradish - 9:46 pm on Mar 4, 2013 (gmt 0)
First off, congratulations - hundred(s) of orders per week is no easy feat.
Second, my advice is to run Google and Bing Ads now.
Not only will you increase sales, but more importantly it will be a good opportunity to learn the ins and outs of pay per click advertising.
Organic search traffic is great. I've been practicing SEO since the late 90's and absolutely love that kind of traffic... but search algorithms are changing constantly these days so I think it's always wise to diversify.