Most achievements are about skill or a grind. But some are just totally random. Take archaeology for example. A lot of grind but also a fair dose of random in it too.
So today when I got this achievement I was pretty pleased!
Those stupid decoded messages from Blingtron are so random. I am sure if I kept doing Blingtron everyday I'd get it eventually but it was so good to get it today! Also, the achievement is not account wide so you have to keep doing Blingtron on the same toon - not such a big deal for me since I don't have alts. However, doing the Blingtron daily is account wide so maybe it makes sense.
I actually saw the message and was about to vendor it and thought oh wait, I better open it just in case, and it WAS the one I needed!
So yay for a random achievement. Now I should get back to those real achievements that actually require some work and effort...