Exactly. I have read a couple examples of people getting both bonuses after 7/19, but the terms of the United card do read that you can't, so just be aware of that risk if you go for both. (Though oddly the CO card doesn't seem to have those terms).

To be more on topic of the thread, I don't know that you should trust all bloggers, or trust no bloggers. There are many miles and points bloggers who talk about credit cards, and everyone approaches it a little differently. I know I would never link to an inferior offer if I was aware a better offer existed. That said, none of us know everything about every card at every second, so mistakes can happen. However, the majority of bloggers that I know and communicate with do try very hard to research and promote only the best offers, at least in their posts.

As has been pointed out, there is a business element to many (though not all) of the blogs most of us read on a regular basis, but that doesn't mean that it is good business decision to promote sub-par offers. In addition to it not making good long-term business sense to promote lesser offers, many of these bloggers actually are nice guys (and gals) who really do want to help people get the best deal they possibly can.

Do your homework to compare offers on various blogs and forums, but in my (albeit biased) opinion, many bloggers aren't the evil empire looking to trick unsuspecting folks into signing up for an offer that provides a smaller sign-up bonus than another publicly available offer. If that is the opinion you have of a blog that you read, I recommend reading a different site. There are plenty to choose from, and obviously some are able to do a better job staying current on the top offers than others.

Blogs certainly aren't perfect (at least I know mine isn't), but when they operate in conjunction with forums, such as Flyertalk, everyone wins by having tons of free miles and points information available at their finger tips.