Google implemented two major changes this year that had an impact on the ranking: Google Caffeine and the Mayday-Update. With the first, Google upgraded their infrastructure to meet the changed requirements for size and speed; this did not incorporate any changes to the ranking-algorithm though. The Mayday-update (which got its name from going live on May 1st) is a different story alltogether: here, Google changed the algorithm to show better different searchresults. The brunt of the changes could be seen in the longtail, which are those keywords that might not get a lot of search volume by themselves but which, summed up, make up the majority of traffic for a number of different types of sites. In the Toolbox, not only do we have our database which gets updated on a weekly basis, but also one that maps the aforementioned longtail. This database consists of more than 10 million keywords and is being updated on a monthly basis. The following analysis refers to this source.

Oftentimes, when Google changed their algorithm over the past few years, it meant that they were putting more weight on the domain-trust, which is the trust that Google has in the quality of a domain. While this might not necessarily increase the quality of the top-10 results, it does decrease the likelihood of there being major discrepancies. To test for this, I took the amount of unique domains in the top-3, top-10 and top-100 both before and after the update and evaluated the results:

Amount of unique Domains

	Before Mayday	After Mayday	Change
Top-3	1.787.059	1.776.188	-0.7%
Top-10	3.523.332	3.677.257	+4,3%
Top-100	12.489.205	11.712.946	-7,3%

Sadly, we don't get a clear picture here: in the top-3 there are next to no changes at all, the top-10 actually sees an increase in unique domains and only the top-100 shows a noticeably decrease of unique domains after the Mayday-update. Maybe Google tweaked their trust-dial with this update, even though it seems that it was more geared towards the lower ranks – it seems they are using different signals on the relevant positions on the first results-page.

The following shows those domains that gained power after the Mayday-update, in absolute keyword-amounts. I tried to limit the list to those domains where the changes are very likely due to Mayday and not due to the overall growth of the domain:

Winners

#	Domain	Before	After	Gains
1	facebook.com	896.242	2.067.189	1.170.947
2	youtube.com	2.491.556	3.067.692	576.136
3	wikipedia.org	4.095.198	4.560.067	464.869
4	gutefrage.net	1.976.237	2.349.367	373.130
5	yahoo.com	2.707.498	3.025.174	317.676
6	wordpress.com	1.696.246	1.941.639	245.393
7	markt.de	312.879	508.875	195.996
8	apple.com	427.187	619.440	192.253
9	amazon.com	901.884	1.080.874	178.990
10	yopi.de	823.524	997.778	174.254
11	stern.de	398.104	543.696	145.592
12	zeit.de	403.154	530.112	126.958
13	suchen.de	372.214	473.450	101.236
14	faz.net	473.143	574.302	101.159
15	meinestadt.de	902.981	983.849	80.868

And while we're at it, here the list with all those domains that lost noticeably due to the Mayday-update:

Losers

#	Domain	Before	After	Losses
1	ebay.de	3.635.851	2.645.512	990.339
2	preisvergleich.de	933.573	321.894	611.679
3	germanblogs.de	684.718	155.053	529.665
4	wikio.de	944.819	454.452	490.367
5	folkd.com	666.508	183.144	483.364
6	oneview.de	813.825	346.051	467.774
7	websitewiki.de	641.226	220.494	420.732
8	yatego.com	1.249.758	855.726	394.032
9	shopping.com	1.248.120	915.624	332.496
10	yigg.de	320.992	3.882	317.110
11	berlinonline.de	586.298	269.459	316.839
12	quoka.de	964.070	662.460	301.610
13	hotfrog.de	1.258.969	1.016.121	242.848
14	libri.de	577.631	344.868	232.763
15	linkarena.com	256.489	26.748	229.741

When I compare the sites on the lists with my “perceived” quality of their content, then it seems that this update was a success for Google. The projects with unique content now show a stronger presence in the longtail, while those with rather thin content, which is also often not unique, are among those domains that lost the most. It is still not clear which dials have been tweaked, though. I could imagine Google putting more emphasis on onpage-factors for the longtail again, while we also cannot rule out that they are using (sidewide) factors like bouncerate and the time visitors stay on the domain.