I wouldn't be surprised Alan looking at his website that a lot of links were built naturally by people linking to his site as it looks like a good resource.

I've got a website were I built some links to gain a good position and left it, over a few months that exposure built tons of new links without me knowing from all over the web.

Now if those little sites have been hit, lets say a fair amount had been wiped out then I can see how rankings could be lost.

no one has actually said to do anything but wait, I will go against the fold and say strip out all those adsense units down the left and maybe even dump that sharing tool bar at the bottom of the page, you already have a load of social sharing buttons on each page and that bar at the bottom looks like its holding up load times.

Go into webmaster tools and request a crawl.

http://blog.kissmetrics.com/guide-to-guest-blogging/

http://www.copyblogger.com/successful-guest-blogging/

I do guest blogging to the best I can and what I usually do is:

Find a few of the best blogs in the niche of the client, I look at all elements - check out the social channel numbers, the amount of social sharing on the posts, number of comments, number of posts going up daily/weekly, length of posts etc.

I will then try and make a headline which fits in with the blog but hasn't been done to death.

I will then usually create a list type article (Top 5) because I feel the information is broken down better in this format and allows for skim reading if the user doesn't want to sit there and read 2000 words (I make sure every heading has an image as well).

The client goes in the byline.

That's just me, im not a pro blogger/writer I just try to produce something I would be very proud to put on my own blog.