There is no rule of thumb. This is thing which you can control. If you bring non-interested ppl to your blog then bounce rate would be much higher. But if you bring ( i mean advertise in niche market (sites) ) interested ppl then bounce rate would be low. So there is no one answer to your question.
Yea, my blog's bounce rate is steadily around 80% right now. I'm trying to aim for a 70% which might be hard to do.
What's a good bounce rate for a site? I get a bounce rate that varies between 45% and 30%. Not sure this is too good. Also does anyone know if Google Analytics has a way to tell how many people bookmark a page and download the favicon? Oddly almost everyone that comes to the site bookmarks it.