On amazon.ie at least, the sponsored products are so hilariously out of place it's dead easy to spot them, and banner blindness kicks in.

E.g. I search for "nuk baby bottle warmer" and the first result is a window washing squeegee and the second is a bathroom grime scrubber.

Works as intended. If you’re looking for a baby bottle it’s reasonable to assume that your house is in disarray from the whole new baby in the house thing, and it’s above average probability that you’ll buy completely unrelated products during your search.