Good point. But I'm not claiming that you should just get any old link [e.g. it doesn't hurt so just get links indiscrimantly]. Obviously with anything "cost" in dollars should be a cautionary note... what are you actually buying?

A link is a vote... and that is proven.

A vote is the bases for Google's PageRank and their idea of ordered ranks... and that is proven.

Thereafter, you should be able to classify votes general good or generally undeserving.

1. A link from dot.gov?

2. A link from dot.edu?

3. A VERY RARE sitewide from dot.gov or dot.edu?

4. A link from any domain of high trust

5. A VERY RARE sitewide any domain of high trust?

6. A link from an info site [a blog]

7. A sitewide from an info site [a blog]

8. A link from an average commercial domain

9. A sitewide from average commercial domain

10. A link from a directory

11. a sitewide link from a directory

Will all of these cause harm?

I say none will on their own... so long as none are also owned by you... because voting for yourself isn't really a vote -- right?

Even if one or all repeats the process over & over again with other domain that doesn't mean "harm" will occur...

What "harms" is you looking for that same process over & over again [e.g. it work the first time it'll work again] particularly if you don't use other linking alternatives.

At some point you cross a threshold and Google can [WILL] negate it all and that means whatever you have left over [which is usually NOT MUCH] is why you see "harm".

Dave's claim is interesting - he had existing links and ranks and he merely added 3 unrelated site links and Google killed all the domains previous merits and ranks dropped... If it was only that easy...

Something doesn't add up... there are missing details in that experiments "because" links are the only thing that get's you ranks in Google... now we're saying they aren't?