While maintaining unique content, do keyword research using Google adwords tool and find long tail keywords and start posting articles with those long tail keywords and get some backlinks, It may give you decent traffic from search engines.

In terms of traffic.. you should focus more on Bookmarking, Networking, Ads sites, you can also do Email Marketing. socialize with others.. like them to like you plus them to plus you.. get intouch with social media groups and communities..

I don't know much about SEO, but I don't think it would be very beneficial to use PLR content as is, as part of your SEO strategy.

If you rework the PLR content to create unique content (in other words, the PLR content is just a starting point), then that's a different story.

Using PLR Content, unchanged
Think of it this way, would you use syndicated content as part of an SEO strategy? Just like syndicated content may appear on multiple sites or blogs, so to could PLR content appear, unchanged, on multiple sites or blogs.

So, from a ranking point of view, using PLR content may not work out as you planned.

If you want to use PLR content, as part of your SEO strategy, then use the PLR content as a starting point and create unique content from it.

So, as an SEO strategy, unique content is better than unchanged PLR content (i.e. not unique content). But, that doesn't mean that PLR content may not result in an increase of traffic.

Traffic from PLR Content
You may not necessarily get search engine traffic as a direct result of using PLR content unchanged, but that doesn't mean that you can't get traffic from PLR content.

If the PLR content that you added to your site/blog was well written and entertaining or insightful, you could still get traffic from existing traffic sharing what they read with others.

Using PLR Content
I can't say for certain that you wouldn't benefit, rankings wise, from using unchanged PLR content (or even using PLR content with only a few changes)... but it does seem unlikely.

But, if you still want to use PLR content as part of your SEO strategy, and you only plan on making a few changes, then the best type of PLR content to use, would be Limited Edition PLR content (also referred to as Limited Distribution or Limited Supply PLR content).

With limited edition PLR content, only a limited number of people will ever use the same PLR content as you. This way, you have less competition when trying to appear in the search engines for the exact same piece of PLR content.

If you are using PLR articles then make sure you are rewriting them, then it is going to work.

be very careful using plr articles, you don't want to undo all that hard work you put in to get traffic in the first place

that being said, backlinks are okay, good backlinks are awesome. Getting organic traffic is all about quality, content, backlinks, page design.