I am a professional website designer here in NZ.
I have built over 200 sites in the past few years.
Most of my clients want to be 'at the top' of Google for their main search terms of course, so i have spend most of the last 3 years helping them with this - closely following Google's own advice on how to get a site to the top of search results. This has been thousands of hours of work and many 10's of thousands of dollars invested by my clients in achieving front page status - all following Google's own advice/ documents as well as other experts and blogs etc. 
Today I spoke with one client who we have had on the front page of Google for their main search terms for the past 3-4 years - but suddenly, they have dropped right off just in the past few months.
We were both at a total lose to understand this as we have followed the book now for years and done everything possible to achieve top spot. We link the sites up at least twice a year, carefully refined meta data and keywords, careful updated and managed content etc etc etc.....extensive!
It got interesting when we started to realize that there were at least two new companies that were now on the top page - and have suddenly just arrived, whereas the client's site had disappeared!
It got even more interesting when we realized that BOTH of those new sites were "Powered by Yellow".
Just in the past few months, I have been made aware by my clients that Yellow have been out pushing their  latest 'package' around the market - making all sorts of what I thought were elaborate promises, and typically over priced, given Yellow online has been failing each year in my opinion to achieve much for their clients, then each year, repackaging their offer and hiring new sales reps to push it.
Now it seems they have suddenly hit the jackpot, and despite competing against well established and built sites that have been around for years, they are somehow able to get their new "powered by Yellow" website customers to jump right in front of the leading sites almost overnight.
THIS IS NOT POSSIBLE IN MY PROFESSIONAL OPINION - AND IT SEEMS CLEAR THERE HAS BEEN A SPECIAL/ UNDER THE TABLE TYPE DEAL DONE.
I immediately recalled an article I read recently in which Google has been accused of "favouring" their own partners and content on search results. This has resulted in class action and anti-trust law suits overseas (you can search for these articles online, one of them here: http://www.theage.com.au/it-pro/business-it/regulator-defends-google-bias-settlement-20130114-2colu.html)

It seems very clear to me now that this is what is happening in NZ- Google have apparently struck some sort of deal with the increasing failing Yellow Group (or their incredibly large and powerful corporate owners) - where by some of Yellow's brand new website customers, who are asked to pay thousands of dollars, can suddenly 'jump the queue' on other website owners who have invested years of time and money following Google's own promises and advice to steadily climb to the top. 

In my view, this is a clear breach of trust (and possibly contract) and an even more clear abuse of monopoly power.

A class action/ anti trust law suit is the answer (possibly also a Commerce Commission complaint, but like most things in Government these days, they seem to favour big business, not Kiwi tax payers). 

If you are a smaller website company that is now experiencing the same breach of trust and under handed tactics - and find yourself at a loss to explain why your customers have lost ground and are now coming runner up to new/small companies/websites in your industry that have just 'sprung up over night', despite having spend hundreds of hours (and thousands of dollars) on your efforts - then I would like to hear from you.

Please take screen prints of the new search results, and save PDF's of any falling visitor numbers as your prized site is pushed off the front page by some newbie who just had to pay off Yellow Pages to get there (it appears).

There needs to be a class action lawsuit taken against this monopoly abuse - equal in value to the amount of money the deal has been worth to them (and Yellow, if I am correct in my assessment), plus punitive damages paid to insure it doesn't happen again.

Given the huge number of website designers and small business websites in this Country, most of whom are apparently now adversely effected by this underhanded tactic (I would say bribe) - this lawsuit could well be in the Billions of dollars - and could then be distributed back to the parties affected by this scam.

Please Private Message me or send emails to: antitrust@maxnet.co.nz in full confidence - and lets start building a clear case to file in the Auckland High Court against this clear abuse of monopoly power - which is rendering years of work and thousands of dollars by good honest, hard working Kiwis, almost worthless overnight - despite having believed and trusted Google's own advice and docs on SEO. 

Cheers!