Do you think submit your link to all directories will give you much traffic?

You will likely get ZERO traffic, the benefit is the keyword optimized anchor text pointing back to your domain. This helps raise your position in the search engines

I think the answer for your question (directory submission) is more to backlinks advantage, not traffic. So more quality backlinks will lead to high ranking, high ranking (in the right keywords) will lead to more money to come in.

Directories are alright, but for the price a lot of them want, you're better off getting a blogroll link or two. Those are generally worth more. Basically, get the free ones and maybe a few paid, but make sure that's not all you're doing.

Any recommended free directories?
I find Hotfrog good.

You will hardly get any traffic back to your site through directory submissions if any at all. The main purpose is gettin the backlink to your site with your selected anchor text, which increases your search rank for that keyword.

No; typically it won't give you any traffic at all.

What it will give you is some backlinks of very varying quality (the free ones will often be worthless). There's a free directory submitter here which will (allegedly) submit your url to 2,500 directories, but people generally say they get very few indexed, traceable backlinks out of it - that outcome seems to be the normal one, though, for almost all "directory backlinks").

It isn't worth mine; no.

I think you're asking about SEO and traffic, really, not about "marketing"?

Link exchanges are also typically very poor-quality SEO, as even the most rudimentary and basic of search engine algorithms can see reciprocal links for what they are (i.e. incentivised) and discount them.

AdWords (and similar PPC systems from non-Google sources) are the fastest way of getting targeted traffic, certainly. I have only a little experience with it, myself, but for those "trying it out", it typically has a learning-curve all of its own which requires the expenditure of both time and money in varying amounts.

Personally, I get very little (if any) traffic from link directories. However, when I was first trying to move my site up in the search results, I did apply to some.

Why?

I went through and analyzed my top 3 competitors for each of my target keywords. I wanted to see if they had any links that I could go get - so that I could start to "close the gap" right off the bat. Sure enough, I found their links on all sorts of directories, so I applied for the same ones.

Did I think I was going to get a bunch of traffic from it? No. I just wanted to do something to level the playing field with my top competitors - while I worked on building better, higher-quality links in the meantime.

Manual Submission of your links to other related sites is a quality way of link building. It is also drive huge traffic to your site.