wheel - 8:58 pm on Mar 19, 2010 (gmt 0)
Payed links will not last forever, not good. So either exchange (some say Google has algorithms to neglect these), or even better produce great content to get natural one-way links to your sites.
If you start trying to define 'paid links' and 'natural one-way links' you'll soon see that in fact, paid links can last forever. Because distinguishing between paid links and natural links is virtually impossible if done right.
I do believe that in most industries, that relatively few of the right kind of links can have a huge difference. It wouldn't surprise me to find out that 75% of my ranking 'juice' comes from about 6-10 of my backlinks.
The links that are:
- 10 years old
- on my subject matter
- huge backlinks, .edu/.gove level
Those backlinks, I think it doesn't take more than a few to put you to the top. Of course getting those few links is generally extremely difficult.