CMP has a “click here or wait 18 seconds” type of ad in the landing page (or probably more/less if you are located somewhere else than UK) on this link.
And this is my way of saying not that directories “suck” but that you should try to get your site listed into the directory that actually shows your entry. Not that CMP is a directory…
But: there are directories that will send you important traffic (like DMOZ and Yahoo!) Why would they actually send important traffic? Because people rely on what they have to offer.
There are also directories that, if you are lucky will send you some traffic, and if not, they will give you some link juice. And these are Best of Web, Aviva and the like.
Last, but not least, there are the directories that, apparently, will give you nothing: close to no traffic (one visitor per month doesn’t count, but what if that visitor also converts?), little link juice (no SEO value?) and so on.
The negative aspects of random directory listings could easily be ignored if you consider the potential traffic value, but from an SEO perspective you have almost nothing to win.
The search engines UNDERSTAND the content of the pages where your entry is listed. They also know how many visitors that web page has and why and sometimes, your own pages rank higher from that point of view. So knowing that the SE rank your website based on what your visitors think and on the importance of the page linking back to you, are you still sure you want to get your website listed just by any directory?!