How long before backlinks take effect?

[activitysuper]

In general how long would it take for Google to update the SERP after it found the external link activity?

Does it depend on the website the link is on as?

So for example, after it found a link on the BBC would the SERP update a lot quicker then after a link on a small blog?

Maybe Google updates on a certain day?

[matbennett]

There are 2 parts to this really: When will it spot the link and when will the benefit (if any) be applied.

When the link will be spotted will be very dependent on where it is. Higher authority, frequently changing sites get crawled more frequently and the more authoritative frequently changed content on those site more frequently still.

There is quite an interesting Matt Cutts video about how this works here: http://www.seroundtable.com/how-google-works-video-15055.html

Once Google is aware of the link it becomes much harder to say when that benefit then gets applied. You are probably going to see a few suggestions to this answer, as It is something that gets debated a bit. In truth it is really hard to measure in real life cases. Assuming that 1 link is enough to move the needle and you could somehow measure its effects in isolation I believe it is somewhere between "as soon as it is indexed" and "a few days". I don't believe that the old period recalculations still apply.

I think that the easiest way to test that would be via long tail anchor text. Anyone know if anyone has done this already?

[activitysuper]

Thanks for quick reply,

I understand the first part, I was really looking for answer to the second part 'After Index', which sounds like it's a bit of a grey area.

See you say a few days and I would be inclined to agree but I have in the past created 5 links in a few days, stopped all activity and 8 days later then seen the movement.

I like to put myself in Google shoes and think what would I do and in this case, most likely want the link crawled more then once to make sure it was a genuine link.

So with this in mind maybe it's down to how frequently the link is found, BBC link could be found 3-4 times a day, where as a blog link could be found once in a week.

Just a thought.