Directory Submission.

Both are beneficial but if we do more and more SBM it will be harmfull.

directory submission is best

Try linkcollider.com

bookmarking is better than but directory submission for long time .

I think Social bookmarking is always best than Directory Submission.

Use Bookmarking effectively to build links for your websites , its the fastest way to build links.

How often would say you should post to social bookmarking sites? I'd imagine if you do it too often it will be seen as spammy.

social book marking is good for getting the backlink . directory submission takes a time to approval. that's y bookmarking is better than the directory submission.

Directory submission is good if it makes active link. If it doesn't make active link then social bookmarking is good option.

Directory Submission is the best

Both are the good way to getting traffic for it and directory also help to getting back links for your site and it help you to getting ranking high in search engine your keywords but you should use high pr sites for submission.

Bookmarking is the best now days because penguin is updated .Recently updated penguin only higher PR site takes for the bookmarking and Directory for the long time means 6 months.