Weird change in amount of links

[alsvik]

We just went from 50.000 external followed links to more than 150.000 ext followed links within a week. At the same time we went from just below 200.000 total links (internal/external) to more than 650.000 links and linking root domains dropped from around 750 to below 500. We don't do linkbuilding. We don't use a seo-agency. We do all stuff on our own. So why this major change and what impact will it have?

[BenFox]

Have you recently made any changes to an affiliate program or banner ads campaign?

An extra 100,000 links is actually pretty easy to come by - it could be one site with dynamically generated pages linking to you. I wouldn't be too worried about this but you may want to look into it for your own peace of mind.

With regard to your linking root domains dropping - do you have any records that show what type of sites have been removed? It could be that you had a lot of directory links which Google has removed from the index. If this drop in LRDs hasn't already led to a drop in rankings then, again, I wouldn't worry about it but you may want to look into it further for your own peace of mind.