If you are using right keywords and good ads, then probably the problem is your product or the landing page.
Try this - product name - productname - productname com don't put too much faith with wordtracker though
research, plan, execute, test and Tune. Dont stop after setting up one landing page. The biggest results i have found are split testing using different variables to figure out what triggers the highest conversion for what i am marketing. Landing pages can be very important to build up your sales for the main product. Something else to consider is make a review and comparison of two of the top products to give your traffic a reason to want to buy that product through your page. Tracking is also very important. Separate your keyword campaigns and figure out which ones are converting and which ones are not. You may be making a little money with ill call it "a beginners adwords campaign" but i do think the profit is there if you tune it correctly to squeeze sales in the right areas and cut your cash guzzling keywords that dont perform. Think about it this way too. You may invest $600 to make $635 but there is valuable information there if you tune your campaign you could cut the non performing keywords like i said and the rest of the money your not spending is a good profit still so even if you cut it in half and where able to make 500$ from $300 thats $300 you could be spending on another adword campaign and $165 more then you where making before! So dont just drop what your doing for a new project quite yet! Tune it and get the most out of it!