Andylew - 8:43 am on Jul 20, 2010 (gmt 0)
I posted this in another thread but I think it is also very relevent here.
We have at long last pinned down exactly how mayday affected us, this is after months of our own speculation and theories and many hours hard work.
The facts that were known to us:
1st may = 90% drop
Algo update confirmed by Matt saying 'looking for higher quality pages'
Caffine official launch start of June
WMT still reporting a massive number of indexed pages from sitemaps
Site: Reporting 10% of what WMT is reporting.
Small changes back and forth over may/june/july but nothing significant.
What we are now 100% certain what happened to us on May 1st:
The algo update was a tweak upwards to minimum link juice a page has to have to be listed in the main index. Therefor although many pages might be 'useful' if they dont make the grade they are dropped to the supplemental index (yes it does still exist).
Caffine has nothing to do with Mayday
This can be checked by comparing site:domain.com which will give the number of main indexed pages to "site:domain -spellingmistake" (without quotes) which will confuse google into giving all pages in the main and supplemental index. Notice any difference?
So whats the solution?
Simple, as Matt said deep links, and more links. More deep links are required to get link juice ripples further down into the site and more links to the home page to increase the strength of the link juice ripples into the main body of the site. This is an automatic system so once a page reaches the minimum link juice level it will then be ranked in the main index.
The problem for our site and im sure many others will be the number of pages which is probably why it was so badly affected, with lots of pages the link juice has been spread more thinly amoungst its links and these pages have now dropped below the minimum link juice required for main index listing.
Pre mayday minimum link juice might have been 1. So:
Homepage link juice 10 links to 10 other pages.
Each linked page gets a share of that juice so 1 juice each.
Net result = 11 main indexed pages.
Post mayday minimum link juice was increased so say if it was increased to 2 then only 1 page would then be in the main index and 10 in the supplemental index.
The net result of this is loss of quantity of traffic but the traffic generated will be highly targeted and likely to convert - the supplemental index would only be dipped into when the main index falls short.
For all those 'waiting' as we were I no longer belive this is just a short term 'problem', it may be tweaked slightly which may just tip the balance back to main index pages but overall this is here to stay and the answer is more juice and deeper juice!