You are a pro Chris. I admire your knowledge. Your e-book sells worth and unique information. I wonder if you offer an affiliate link. I will sell a few and buy it from the commission!
Also a word of measure on these sites that do provide backlinks. Google has been on to this for years. If you do not get a high number of votes (at Digg it would be at least 30 to 50 Diggs) Google discounts the bookmark for the most part. At some point Google is going to start seeing this as a negative indicator.
If you use social bookmarking sites incorrectly you can seriously damage your Google rankings. If you are only going to submit to these sites to get one measly link then you are wasting your time.
Read the forum thread about Google link juice.
Then think about it like this. If a social site has 10 million registered users (Digg does) and each one creates just 5 posts. That is 5 million links. Do you think that one in 5 million links is going to do you any good? Especially when Google knows that the links are being created at times for self promotional reasons.
A site only has so much link juice it can pass on, that is why you only start to see social bookmarking sites show up in results after they have some other votes for the item.
Participation will do you more good than posting your own links and that is mostly what I teach. Spam tactics will just get you known as a spammer.
Thanks for you links and the post on your blog but I am going to prove you are doing it wrong and if you do it my way you will easily get 100+ Diggs but you have to start doing more to position yourself. You have to do more than just submit your own content.
Post your Digg profile URL so I can take a look at it.
Okay, so I have you at 7 Diggs and it took me 10 seconds to do that.
That is what we are here for. Once I have collected the last of my content research I will have something very good for you all, just gotta get the last of the research in.