As I mentioned in the ALT Tag seo tip, some seo proclaim putting your keywords in bold or putting your keywords in italics is a benefit in terms of search engine optimizing a page – as if they are working their way through a check list.
It’s impossible to test this, and I think these days, Google might be using this to identify what to derank a site for, not promote it in SERPS.
I use bold or italics these days specifically for users. Only if it’s natural or this is really what I want to emphasise!
Don’t tell Google what to sandbox you for that easily! I’m currently cleaning up the Hobo blog to reflect this, too.
I’ve been meaning, maybe forgetting, to pint out in these posts I think Google treats every website differently to others in some respect. That is, more trusted sites might get treated differently than untrusted sites.