I think the problem here is that a lot of people are thinking of Fiverr as a place to commission backlinks for their website. There's a lot more to SEO than that. So, here we go, some tips for use of Fiverr:
1. Use Fiverr to get SEO analysis done. Just need a few hours worth of work to analyse a competitor's backlinks ... or even your own? Well you can't buy subscriptions to the best IBL and SEO analysis software by the hour. You have to pay by the month (though some do have free trial subscriptions). It's far cheaper to hire someone in Fiverr to do it for you. Many of them have fully paid up subscriptions to Moz, Ahref, OSE, SEMRush, whatever.
2. Same thing with press releases. Some of these Fiverr people are signed up and subscribed to PR places like PRBuzz and can publish your press release for $5. Save yourself the $299 annual fee that PRBuzz charges! Submit multiple releases to different PR agencies (with the copy slightly different in each one) and save yourself a lot of money!
3. If you're #2 or #3 for a money keyword and you aren't able to move up a couple of notches, it's not unusual to commission someone in Fiverr to do some SEO for your competitor who's hogging that #1 spot. A couple of hundred quid on that may get some real results. It's a dirty trick and I've never used it, but negative SEO is like sh*t; it happens. I believe the top method is to get your Fiverr guy to spin content and dump low value articles all over the place with links to your competitor's page. Then there's SENuke, Xrumer etc
4. Use Fiverr to get links but have the links go to your Facebook or Youtube page rather than your money site i.e. use filtering / tiered sites. Or better still use multiple layers of filters to not negatively impact your money site! Is there any benefit to that? Who knows. Some swear by it. Maybe it's about
how you do this.
5. Want local action - citations, reviews, a complete Web 2.0 profile - built from a specific location? You want Fiverr. Much better than signing up for a bunch of proxy IPs and doing the work yourself.
6. Then there's voiceovers for your videos, creation of infographics or images for your articles, all kinds of other SEO value to be derived from using Fiverr wisely.
But, yes, you need to know what you're doing. Signing up and buying yourself 50 "high PR" links for $5 ain't it.