Important page content should physically exist at the top of each page. Currently, all pages on a 3dCart site have the code laid out roughly the same way as the visual flow would suggest. In other words, the menu, the header links, etc., are in the top of each page. Search engines like to see the unique content of each page at the top of the code.
So, for instance, product pages should have the descriptions and images as close to the top of the page's code as possible, instead of down at the bottom underneath everything else.
On a randomly-chosen product page for a massage table on our site (www.bannertherapy.com)
, the description of the table starts at line 902 (out of 1,662 total lines). The product's description could, and should, be placed much higher in the page's code.
The overall point is this: The layout of a page should be independent of the physical location of the code within that page, which should be optimized so that search engines see the most important parts first (meaning that the important elements should be placed as close to the top of the code as possible), while they are positioned visually (using CSS) in a visitor-friendly configuration.
We lost nearly half our traffic when we switched to 3dCart, and it has stayed that way ever since. I don't know all the reasons, but this particular SEO
tip is one which I followed on our previous site, and one which the folks at 3dCart did not. I'm sure this oversight is not solely responsible for the drop-off, but fixing it could only help.