Bounce Rate: How much is considered bad

I just checked my analytics on a client site. Over the last 30 days his bounce rate was 1.7%. His site is consistently less than 5%. It has the lowest bounce rate I've ever seen for an extended period of time. People like his material.

What bounce rate is appropriate would depend on the goals of the website.
For example on a Micro Niche site where visitors leaving through your Adsense links is the goal -- then I want as close to 100% as possible
They arrive on the page and leave through an Adsense link - therefore a 100% bounce rate.
Or if I have a single sales page where the order link is on Clickbank, or another 3rd party site - once again I'm shooting for 100%
Course those who leave your site via the back button will be in that mix too.

If I have a store selling products then I want the bounce rate to be as close to 0% as I can make it.
Realistically you aren't going to get a 0% bounce rate. There will always be someone who arrives at the site and then leaves right away as they see it wasn't exactly what they were looking for.
My stores run around 55%
The other thing you have to remember is a person does a search and lands on one of your pages via the search - if their search was specific then perhaps they don't need to go any further on your site.

So, to answer your question on what percentage demands attention? It all depends on the site and how your traffic is arriving.

If the visitors are arriving via organic results then I don't worry about it.
If the visitors are arriving via PPC and leaving right away then I'll be having a fit as thats costing me money. I'll have to make sure my ads, keywords and landing page are really dialed in together to prevent wasted clicks (wasted money). This example would be for a store.

Hope that helps

5% ??? He/she must have some serious repeat visitors. That's out of control for 'new visits'...

I've never got a site below 35%, and if I get 45 - 50% it's a victory

Bots skew it a lot, so it's not most accurate rep.

A bounce is counted when a visitor leaves from the page he/she has arrived at - another words leaves before visiting any of your other pages.

Example - arrives to the index page and leaves through a link to another site or through an adsense link - its a bounce (they are leaving your site)
-- Arrives to your site and leaves via the back button before visiting any other pages - its a bounce.

-- arrives on any of your pages and then goes to at least one more of your pages before leaving - its not a bounce.

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As for the low bounce rate on Jay's site - I don't think its necessarily repeat visitors - its just that his material is pretty entertaining - or at least thought provoking.

The 1.7% he got over the last 30 days - 85% of the visits were new.