1) I think it helps but you know what they say about opinions.
2) Will they supply a list of pages you can see your links at.
3) Well Fiverr is 5 bucks so it's not like you're breaking the bank.

If I was going to buy backlinks (I wouldn't) it certainly would not be from Fivrr or Freelancer.com. There are other places out there that have offered this type of service for years that are far better at masking paid links than some third world freelancer is going to be.

There is also some good services are available so you can try yourself to find the good one to your website and build it.

If your buying links are good quality then its definitely help your website, So, make sure your backlinks are from the good authority websites.

As buying backlinks is often the quickest way to acquire them. Google clearly states that buying backlinks to improve your rankings breaches their guidelines.
you should follow these guidelines:
- Buy links individually instead of in packages.
- Deal directly with site owners instead of with 3rd party companies.
- Don't buy links from sites that openly state (on their site or elsewhere) that they sell them.
- Buy links from sites that are relevant to your own site.
- Buy in-content links instead of links in the sidebar or footer.
- Buy links on individual pages instead of site-wide links.
- Keep the percentage of paid links below 10% of the total number of links your site has.

Just to throw in my 2 cents. You can target article writers (how do you think they make their money writing on Forbes and such, people ask for their services!) and ask for them to include a link to your content with an upcoming article and offer some money for it.

Link should be relevant and Google should consider that as natural link and count it while calculating your ranking. In this case I would say YES - such links are useful.

Its fruitful to some and not so fruitful to others. You have to always look for long term success, instead looking for short term gains.

Its a better to hire an SEO company or digital marketers for this either paying for backlinks

I just give you one simple tip just keep it in your mind while buying links the website should be niche to your website.

Negative SEO definitely exists but is not the most important threat that you could be lead to think. Simply because search engines are much more clued up than they once were now recognize indications of negative SEO much more effectively, just as they possibly can recognize deliberate efforts to manipulate rankings by buying links for your site. Sure, it's not an exact science and so they do get it wrong, but not often.

Free backlinks are always the way to go. You build your business for long-term success that even your kids can eat off of. Google, Bing, and authorities within any niche never frown on this type of behavior. PLUS... You become an authority in your niche and more smarter because you have been recognized as an authority based on how you approached your business.

Quicklinking can be fun too. It just sucks when the search engines come crashing down and your site no longer receives all the traffic and income it once had.

The other method steadily grows your business. When the search engines make updates the reverse happens. Your site thrives because you have done your research, you properly formatted your site or sites and now it thrives even further because the junk on the SERP's have been removed. Now all they see is your site for keywords you did not even optimize for, let alone pay for.

Well if you are using those links as Tier 1 then they can be harmful. Be safe and use Fiverr links as Tier 2 or Tier 3.