I'm going to resurrect this discusssion as this (and my last paragraph about PPC) have been on my mind heavily the last month or two.
I was doing SEO for about 15 years up until about 5 years ago. This goes back to the "good 'ole days" where things like "Doorway Sites" worked amazing. But of course, Google spent thousands of engineering hours to continually change their ranking algorithm to where all these older "Black Hat" and most "Grey Hat" techniques no longer work (or worst, get you penalized or banned.) And they'll continue to battle them and they will continue to win with the resources they have.
My work focus shifted elsewhere mainly to running my two small businesses, one totally unrelated to Online Marketing Services. Essentially what happened in my opinion is that Google has gradually given more and more importance to one of the least discussed probable components of their ranking algo: site stickiness. You see, back in the old days, before Google was #1, some of the search engines, the sites were actually manually reviewed by an army of human reviewers. As the web grew this was no longer possible of course.
Who do you think after examing a page can determine its relevancy to a particular search term, and company/service offering quality? A computer or a human? Well I still think a human can, but the AI aspects of ranking algos are getting pretty damn close. The most discussed aspect of SEO is typically backlink profile. What do you think is the primary driver of generation of "real/natural" backlinks? Typically for the most valuable backlinks, It's a HUMAN that maintains another website, making a decision with their human brain, to add a backlink to you because they think your website has something good enough to offer people who visit their website.
But there is another human aspect over the years I see rarely discussed in all the SEO articles published. It's what I call 'site stickiness' and in my opinion it has gradually become more and more of ranking factor that Google has been typically very quiet about.
You see, the links to the sites in all the search results are all redirects. They first take you to Google, and THEN to the target web page. So Google can record what keywords you search for, and what results page and the ranking position of the search result you clicked on. If go to a site and quickly assess it doesn't have what you are looking for, you go back to the search results page and typically click the next search result listing. Google can calculate then the time you spent on the website before. If you spent little time there, that's a very negative sign that that web page is relevant to the search keywords you used. If you spend a lot more time than average at a website for a particular search, or don't come back at all, Google can infer that you probably found what you were looking for. They can distinguish finding what you were looking for from just giving up and not coming back by other users searching using similar keywords and going to the same websites and coming back.
So essentially by analyzing millions of users' click-thru and return patterns for billions of search queries, they essentially create an army of volunteer human manual reviewers without those reviewers even knowing they are essentially working for Google to help determine webpage relevancy and quality. Combining this with all the other ranking factors is what makes their results so spot on. This is also why the SEO Mantra in recent years has basically evolved to "create quality content." If you have lots of relevant quality content, the visitor is going to spend more time on your site than average for similar sites. And as I postulate here, I think that is a huge ranking factor in the algo that is underestimated, or at least just not talked about much, the 'site stickiness.'
Starting about 7 years ago, I used Sarkar because I just didn't have the time anymore to do more SEO and had a new company that I wanted to boost the rankings on sooner than later. These guys/gals basically all use the same techniques and are just in a pattern of cycling out the old ineffective websites they use with new ones and experimenting with different combinations of techniques. Initially, Sarkar's (and similar methods I assume) were quite effective. He could move me from a page 2 or 3 ranking to top 5 fairly quickly in most all but the largest niche's/industries.
As the years went on, and Google changed its algo, I saw the changes from buying these services get less and less. I also noticed a disturbing pattern. (1) These guys all ask you to post here that you placed an order. This is simply to keep their service's thread in the forum constantly growing so it shows up near the top of the discussion threads. A crafty strategy but a bit 'scammy' in my opinion. (2) You will see that for anyone that does post results in the SEO Service's Discussion Thread, they are always positive. You rarely see anyone complaining. Why? Because as you point out, the Service Provider will BEG and BEG you to remove your post if you do. Plus people tend to not want to publicly acknowledge they wasted their money. No one has the balls to use these guys' services for several months for several different websites and show a complete study of the results which views as a whole, are actually typically not that impressive.
Are these services a scam? I don't think so. I think they have value in certain circumstances. The circumstance is where you have a new website that since it has no backlinks, it's maybe on page 2 at best or page 3 or greater depending on how competitive the niche is. So you have people that have started businesses that are DESPERATE for more traffic. The services typically can easily take a site from like a 25 or higher ranking to the 9-12 range depending on the site and niche. That's an impressive jump for most site owners. But in reality, especially if your targeted keywords generate 3-pack map results, the value of the ranking exponentially declines as you go from about 4 and lower. So the difference in traffic between say being ranked 9 and ranked 29 is minimal compared to being ranked 3 and ranked 13.
Most of the sites in the top 5 have been around a long time, with large legitimate backlink profiles. None of these services like Sarkar or Samblogs are going to be able to take a site ranked in the 20's to top 3 and keep them there, EXCEPT only if it is a very small niche with very few competing sites.
Instead of spending thousands of dollars on Grey Hat SEO services you would have been much better served by hiring a PPC Advertising Expert to manually and carefully craft and manage your PPC advertising campaigns. Then you could rank in the actual top 3 on the page (above or in Map Pack) and above organic results and stay there as long as you want to pay for it. You could in the meantime continue to develop your site content, get legitimate backlinks (like from Business Directories), write your own blog, post on social media, etc etc, to help improve your organic rank. Organic ranks though don't make Google Money. So over time they have gradually been pushed down by mostly ads, and to some degree 3-pack results (which they don't make any money on the latter, YET.)
One cautionary note about advertising on Google (and Bing). Google and Bings PPC Ad Systems have evolved to be extremely complex with like 10 times more features and settings than they had years ago. One thing Google has done is made a conscious effort to provide AI "Recommendations" on how to set up your campaigns. They've moved this way in my opinion mainly to help the less knowledgeable advertisers get better results, but at the same time it generates more ad revenue for Google. I would avoid "Smart Campaigns" where it's all up to the machine to set up and run everything for you. You need an expert that really knows how to use their system and do things like constantly examine Search Term reports and build negative keywords lists among many other strategies. I can say the Google (and Bing) ad system has grown to have such a large and complex set of features/settings now, there are probably very few companies or individuals out there using their advertising system correctly to keep their Cost Per Action/Aquisition/Sale to a minimum and maximizing the return on their advertising spend. In fact, I would bet the vast majority of advertisers aren't even measuring their cost per conversion at all or at least not accurately.