I’m working through a mixed marketing proposal that covers e-commerce web design, organic SEO, PPC, display, networks (Amazon/eBay), PR, Social Media and affiliate for a new client who sells electric bikes and I’ve stumbled upon a great and easy way of getting some search volume data for the Google Shopping service.
Simply use the Google Insights for Search , enter your keywords, select Product from the drop down, select your location etc as usual and click the SEARCH button.
Now click the export as CSV to take that chart and give you all of the lovely numbers behind it.
If you factor in what you know about your conversion rate from Google Product traffic you should be able to work out an average CTR per position and make some great projections for your future e-commerce campaigns (at least I am LOL).
Get to it!