Big sites don't use "nofollow"

[pokmo]

I'm very new to SEO, so please bare with me. From my experience, a few big sites don't seem to use "nofollow", e.g., Slashdot, arstechnica. My understanding is that there's no point in blasting Slashdot etc., since they're heavily moderated. Anyhow, how much real benefit is there to have a link to my page in one of the comments on this kind of sites?

 

[Autumn]

I would say on slashdot there's not a heap of benefit because since they switched to the new ajax layout, low karma comments won't get shown by default. You would probably have to build some backlinks to your low karma comment to make sure it got indexed.

 

[pokmo]

I would say on slashdot there's not a heap of benefit because since they switched to the new ajax layout, low karma comments won't get shown by default. You would probably have to build some backlinks to your low karma comment to make sure it got indexed.

Thanks for the reply. So if I do have a backlink to the low karma comment and Google indexes the comment through that, would the benefit be the same as if the link appeared on a high karma comment? In reality, how much benefit is this? Could 10 or so such links push from PR6 to PR7? If not, how about PR5 to PR6?