...Each of 20 listings has Samsung keyword in it.
That can be a problem especially when you don't talk about the phones with sufficient detail.
Having paragraphs like this is terrible (excuse me if I can't name the phones right).
Samsung galaxy 1
This samsung phone named the galaxy is a wonderful samsung product
made by Samsung america and Samsung China with precious material
from Samsung Canada with assistance from Samsung thailand.
Samsung blackbox v2
This samsung phone has all features you need from samsung.
It has samsung premiere app, samsung exotic music, and comes
with samsung total care package from samsung japan. Extra support
available from samsung united states. Speak to a samsung rep for details.
Notice how many times I used Samsung? Thats basically keyword stuffing.
What you want to do is make natural paragraphs people want to read and if you can get at least a couple paragraphs on each phone, then you can have one separate whole webpage for each phone.
If you want category pages, then consider using the manufacturer only once then use the names of phones for the names people can select.
the following menu style is bad (ignore creative spelling errors):
Select a phone:
Samsung Black Box
Samsung Girl Specials
Instead, consider this kind of menu:
We have the following phones. Select one from the appropriate
All these i.e. pop up for email, sort and filter section has nothing to do with users google query i.e. "buy Samsung phones". Would google penalize our ranking due to these irrelevant html blocks?
... HTML for pop-up that comes on users first visit ...
This is terrible. The last thing a user wants to see is a page nicely loaded only to find out while reading a paragraph that a pop-up suddenly appears on the screen. That alone is a bad user experience. You're much better off to have an option in the page itself with a simple link to allow the user to subscribe (or to the email). If you must use pop-ups then make them only appear AFTER the user expresses consent by clicking on the appropriate link. For example, add some button on your site labeled "subscribe" and when the user clicks on it, then you can make a pop-up window with the relevant form.