PPC: Improve TOS placement

Hi, I am writing to you because I have been trying to run tests on a keyword for two weeks now.

Specifically, this keyword is the main one, with the most search volume ever for my asin category (it is very relevant to my product)

Previously, this keyword was present in the same campaign as other keywords. I later decided to separate the keywords and create a campaign for each of them.

The goal was to convert all clicks from the other placements to Top of Search.

The strategy used is this:

1. I created an EXACT campaign with fixed bid with only that kw.
2. I entered 0.2$ as default bid because the cpc of that keyword in “product pages” placement was 0.25$ and in “top of search” 0.5$ (in the previous campaign)
3. I entered 200% as the bid modifier in TOS.
4. I waited 2 days to see the results:

– 600 views and 2 clicks in “product pages”, cpc 0.2$.

– 60 views and 2 clicks in “TOS,” cpc $0.32

5) I increased the bid modifier in TOS to 300% and waited 2 days:

– 2000 views and 6 clicks in “product pages”, cpc $0.18

– 30 views and 0 clicks in “TOS”

6) I increased to 400% bid modifier in TOS and waited 2 days, but same results as before

7) I lowered the default bid to $0.15 and increased to 500% the bid modifier in TOS and waited 2 days:

– 2000 views and 8 clicks in “product pages”, cpc 0.15$

– 50 views and 1 click in “TOS”, cpc $0.55

Why is amazon making me generate few views and not winning bids in TOS even with a high percentage modifier?

If I am not mistaken, my bid should reach $0.90 which is significantly higher than the $0.5 in the campaign I had before…

Do you have any advice or any other tests I can perform?