Today we’ve updated our Historic backlinks index, stats are as follows: 352,953,418,877 unique pages crawled 3,529,437,390,545 unique URLs in total. All fresh data crawled in period up to 16 August 2011 was added to this update.
Founder and Managing Director of Majestic-12 Ltd (trading as Majestic-SEO)
Latest posts by Alex (see all)
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I appreciate that there may be no way to normalise your historical data, but when i look at multiple sites on the non cumulative graphs and see a 1000% spike on the same month because your spider has deepened its crawl, I could easily make the mistake of thinking that this was an increase in link acquisition velocity when it is in fact just a data anomaly. Before I realised this I told clients that there was a suspicious spike in activity that needed investigating. now I’m not sure how to trust the whole historic index in terms of trends.
September 12, 2011 at 3:30 pmActually – you will be glad to know there is a “normalize” button in the drop downs that you can use to offset this effect. However – this won’t work on cumulative representations for this data.
While we are here – there are a few other limitations of the data that one should be aware of. The history charts track URL DISCOVERY, but does not track URL DELETIONS – so if a site’s links decay at (say) 10% per month, then there will be increasingly large over-estimations if this chart is used to portray the existence of links at this point in time. The Fresh data is probably a better estimate of “LIVE” links, but with the Fresh index, we do not know whether a link found on any given day is new within the last 30 days or whether it was already in the historic index and just re-crawled – but (in my opinion) a link that has not been seen by our crawlers for over 30 days is probably buried pretty deep and is therefore not very powerful.
September 12, 2011 at 4:01 pmI saw the peak and was wondering what the reason for this was. how often do you actually do this?
September 12, 2011 at 4:00 pmYou can see the dates we update our Historic Index on as we try to make a note of them here. By contrast, the Fresh Index is updating every day in general and is worth using most of the time.
September 12, 2011 at 4:07 pm