As of me, The directories are only for backlinks and not that much visitors eventhough it's a paid directory.Increase the Traffic through Social Media sites
Don't spend on Directories. Spend it on Paid traffic to build a list instead. From PPC to even a Facebook page.
Importance of Paid Directory Submissions Paid directories give you the opportunity to obtain a permanent, one-way link from their high PR website to your site. The flow of link juice results in higher rankings for your website and eventually, your web pages. To maximize the ranking benefits, we recommend spreading the links among a variety of different anchor phrases. Another benefit of paid directory submissions is the targeted traffic that it can send your way from its own pool of visitors.
It depends. If you have a new site, it does help to be listed in a few paid directories. I'd stay away from free ones, though. Unless it's Crunchbase or something. Free directories are mostly link farms or sites that serve ads. Links from them can actually hurt your search engine rankings .
They can send you targeted visitors from their link detail pages. Because those pages receive organic traffic if you submit your link with a good title and description. Link detail pages are not available for the free version of php link directory script.
I agree with @atsad Directory will be useful for both might try to get listed only on top ones as many junk directory sites are available but they are not much worth make sure to check the site in detail before listing on it
Lots of dangerous, obsolete advice in this thread. Paid links are a good way to hurt your rankings in Google. Here's what Google says: "The following are examples of link schemes which can negatively impact a site's ranking in search results: Buying or selling links that pass PageRank." https://support.google.com/webmasters/answer/66356?hl=en