Twitter does certainly have a place and will continue to make ground in advertising but the advertising opportunities will be very limited to high profile people with massive follower numbers.

The benefit of blog advertising has various levels and elements.

I also don’t see any relevance to nofollow on this topic as Googles policies state all advertising and affiliate links must be nofollow and it’s been that way for a long time. I don’t think it’s likely to change either.

1. Reviews – good for up to a week or until the review fades into the archives
2. Topical posts – integrate an offer that has longevity into a pillar article and it could continue to earn revenue well after it has faded into the archives.
3. Banner advertising – most profitable once you have a solid readership, but this is essentially never ending. It’s 2 fold effect is that the banners can either be direct sponsors or affiliate promotions.

Twitter on the other hand is only useful if your followers see it or if your lucky enough for someone to be searching for your tweets. So you circle of influence needs to be much more far reaching than your blog to get the big offers from advertisers.