No I think it's always been that way, it will also bold key word and sometimes even word key and wordkey.

I noticed this today as well... I'm pretty sure this is relatively new, or at the very least the broadening of what may have been happening on a limited basis before. A few weeks ago I split up a "Keyword widget" campaign into separate "Keyword widget", "Keyword widgets", "Key word widget", and "Key word widgets" ad groups just so I could get bolding without using dynamic keyword insertion. With this new change, I don't need to do that because "Keyword widget" in the ad text is bold even if "Key word widgets" is the search query.

[edited by: Rehan at 1:45 am (utc) on May 21, 2007]

I just noticed that Adwords is bolding not only the exact keyword I searched for, but also variations.

Good catch! I am noticing definite changes, too, in cases where I'd created specific ad texts to accommodate for plural vs. singular versions of keywords... now, either one seems to get bolded - which certainly wasted my effort a bit...

Perhaps there are nuances that are new, but one of the first things I investigated over a year ago has to do with this. In our niche there is a common typo, "widgetdance" when the correct English is two words. I found that widget dance, widget dancing, widgetdance, and many other variations displayed bold in both the organic and adWords results.

I'm seeing words like "Condominium" bolded when I search for "Condo", and "Rentals" bolded for a search on "Rent", "Sport utility vehicle" for a search on "SUV", etc. I've also got longer tail searches incorporating the term "rental" returning search results where words like "Housing" and "Apartments" are bolded.

The most broad bolding of words is definitely in the Google Maps OneBox and in the sponsored results... organic result broad bolding is definitely there, but on a much smaller scale. Definitely an "expanded match" symptom. Now I'm just waiting to see the wrong cities bolded for local searches like they did with my adwords account.

Even if your competitors didn't take the effort to use the exact keyword in the ad copy, they'll still get bolded. I don't like it. This seems to make it harder to stick out.