They are sure still one of the best ways to build back link,but you must stay consistence if you are looking to really make an impact on your site.
Yes, I think so. It works for my sites. I have observed though paid links are better because you can be sure of its quality. But if you have a tight budget, free directories are OK.
Yes, of course it's still worth this time for link building progress. But if you hope to getting traffic from there, it is nothing !
No. Directories are practically worthless now. Google has almost completely removed all SEO benefit you gain from directories. The only directories that still carry any weight at all are article directories, and even their weight is now heavily diluted.
Both still offer some value. Not nearly as much as they used to. DMOZ still passes benefit because they have extremely picky criteria, and they weed out most of the junk submissions (probably 99% of all submissions are declined). Yahoo not so much anymore. Google greatly reduced the amount of SEO benefit directories passed on to other sites a few years ago. Feel free to research the topic. I recommend Google as your research tool, but any old search engine will do. There are hundreds, maybe even thousands of articles written on the subject.
Directory submission is the best practice to build links. If keep your regular practice will be effective
Surely, directory submission is a good way to gain backlinks. Still, I advice you to submit your site only to qualitative directories. According to the effectiveness, well, it depends on what you see as "effective". If you mean having a lot of visitors, than it isn't. It only helps your site being noticed by search engines. For example, it helps to get out of Google's "Sand Box".
Directory submission is still a Great work to build back links. Because, most of the directory provides permanent back links. Do directory submission in high quality PR sites like DMOZ. It results huge traffic, PR, top ranking in SERP & quality back links.
constant directory submission is good way for back links......but there should be a quality directory submission......
Go for DMOZ directories..they r absolutely fine...ya..not to expect traffic..u can increase PR..but i still doubt.as i got to hear that..atm..directory submissions are not really going good with google