Links from which type of sites will effect the SERP's!!

[mediadrug]

You have also given the answer to your query. I agree with you partially not fully. Not all site give dofollow links but some give. See this blog  - https://ezinestack.com/mobile-phone-buyi...edit-card/
And https://deals.megamobiledeals.com/ has published their guest blog here and it is dofollow link. 
We have seen the varieties for dofollow and nofollow links from tried party sites. There are several forums also who provide nofollow link with some provides do-follow links. But all time we should not focus on dofollow or nofollow. We must consider the traffic of that third party sites.

Even if you get a link from BBC. Still it won't matter in your rankings if its a no-follow.

[simoncuper]

Relevant sites sending to relevant sites, try diversifying your collection of domain extensions.

[sanjana.mishra]

Hi,

Try to do as many guest post as possible because guest posting site have low outbound links which will help to improve website ranking. Also, through guest posting you get follow link which is more than enough. Try to take links from relevant site. Or you can also do link insertion, is also the best way to take quality links.

Hope it helps!!

Thanks!!

[sophiawils59]

Link from the authoritative site relevant to your inch helps you a lot to improve your SERP ranking!!

[simoncuper]

You want the sites with
- fewer incoming links than yours
- fewer outgoing links than yours
- follow links are better
- higher DA than yours
- no spam comments on those sites

To -
- post article in any and as many forms as possible
- get enlisted on their articles or pages

[RuskinF]

Links from any and every source have an effect on the SERP rankings of your blog.
If you get links from the spammy sites on the internet then the spam score of your website will increase as well.
If you get links from quality websites then the SERP rankings of your website will improve as well.

The factors that judge the SERP of your website depend upon Relevance, variety and Authority.
I hope this helps!