I think few things that has really changed for me over the past year are:

• A greater appreciation for the amount of data the search engines are working with.

• A realization that links that do not drive traffic and are not from authoritative sites will likely eventually drive no value.
• A greater appreciation for viral marketing as it relates to traditional SEO.
• Price points matter. If you make something free market forces will move to drive it's true value to nothing.

Having said all of that, would you think

• sites that offered free links

• and advertised on SEO sites
• and link back to spammy sites offering a free directory that many spammy directories are powered by

would drive much long term value?

A year or two back the whole conversational bits of the web were sorta just kinda being felt out and were perhaps a bit slow moving. Now there is enough various feedback mechanisms that can be tracked to where I wouldn't suspect primarily commerce related directories that were highlighted on SEO sites that provided free listings would drive much value, at least not for Google.

Another tip for any link selling company that wants to sound like they deliver long term value and quality links that work while also appreciating the whole risk vs reward concept...don't use buy-google-pagerank in the URL.

As Martinibuster always preaches, thinking outside of known SEO circles is a good way to do well with SEO.