C-Blocks: Bad Neighbourhoods

The C-block debate has raged for some time in the search engine optimisation community. People new to the industry may find this topic a little confusing, so here’s an explanation about it and how it can affect your SEO.

Every computer is given an IP address which consists of 4 blocks of numbers separated by dots from 0 to 255. C-blocks are the third set of numbers (AAA.BBB.CCC.DDD) this is your cosy little neighbourhood which other sites inhabit.

For SEO agencies and professionals the question is often raised “Are links from the same C-block bad for SEO”. The answer depends on the intent and your overall linking profile; it really comes down to diversity and relevance.

I’m sure there are many sites who have done very well by obtaining links from other sites in the same C-block. But it is also possible some sites may have had links devalued or discounted because they are from IPs which are very closely related.

Having a dedicated IP, i.e. not shared, has value but many many sites do very well without this. There are opinions that apparently explain if you own lots of sites on the same C-block that are very similar and all interlink this can be detrimental to your ranking. This could be true especially if it makes up the majority of your linking profile. Anyway, there are so many other ways to build great links there is really no need to rely on interlinking between your own sites.

Some affiliate marketers have lots of different niche sites offering closely related products even go as far as using multiple hosting accounts so they can interlink, but managing multiple hosting accounts can be a pain and the risk versus reward is questionable.

On the other hand there are legitimate reasons why a dedicated IP can be of use. Sometimes sites can be wrongly accused by search engines and be tarnished by a brush unjustifiably because a few spammy sites make the neighbourhood bad. Once bitten twice shy a dedicated IP can protect you from this. Companies with lots of sites may want to link sites together to cross and up sell products or provide related information having these sites on dedicated IPs may make these sites appear to be less related and protect them from bad neighbourhoods.

However, there are plenty of ethical sites in bad neighbourhoods that appear not to be affected, so it really comes down to personal experience and how the sites are connected. Having links from a diverse range of different quality sites on different C-blocks is beneficial and is a link metric used by many. If you want to be prudent go for a dedicated IP but there are lots and lots of sites who do just fine without.