On the product list
- Avoid all types of ads above or within the product list
- Avoid text ads below the product list
- Avoid overlay dialogs on page load
Other prime locations
- Avoid highly graphical ads in prime content locations on the homepage (especially when it comes to competitions and discounts)
These are fine
- Graphics that adopt the characteristics of the site (background, text colors, fonts, etc) and avoid visual boxing are less likely to be perceived as ads.
- Adding ads in the sidebars is fine, as long as they’re not mixed with filters or sub-categories.