Okay, maybe that's a little extreme. But not much. If you look at the criteria that most of the better search engines look at when evaluating content, way up on the list is "content uniqueness".
What they, meaning Google, is looking for is content that is both compelling and real. One way they evaluate the realness of a document is by who unique the content is. Are there copies of it elsewhere on the web? Does it look vastly similar to other documents? Or is there even a pattern to the documents on your own site? Are you yourself repeating this document with only one or a few words changed?
The reason this is important to Google (and Bing, Yahoo! etc...) is because they are looking to provide the best possible content to their visitors. If yours is real, then it is going to rank well. If it is unique, then there will be a definite pattern that stands out from all other documents.
One sure way to find real documents is to watch what is being read and what is being linked to. Real documents are unique and fall directly into this category because they provide unique value to the reader. This is not lost on the SEs because it is in fact exactly what they are looking for.
Search Engines are always watching for content updates and always watching and comparing your content to content elsewhere on the web. If you are taking content from somewhere else and using it to fill out your own site, not only are you breaking the law, you are really hurting yourself. Potentially catastrophically!
If you duplicate someone else's content, in some cases a SE will penalize your site as SPAM. Not only does this hurt your rankings, it can potentially be much worse. If the content owner happens to scan the web for his own content, they will find your website. If they decide to pursue you, they can have your site turned off quite easily. They simply report and swear under penalty of perjury that you stole their content, and the ISP is required to turn off your website.
But you wouldn't do that anyway, right? You're looking to get great ranking and actually accomplish something with your website, right? So write your own compelling content, or pay someone to do it for you. Don't steal and don't meld something else into some words that just fill space. Do it correctly and you will succeed!
The final point I want to make here is that content is the most important part of your website. And although the investment does not need to be a big one, it is well worth considering paying well to have good content written for you. Unless you happen to be a proficient marketing guru, eh hmmm, it is worth it to hire someone else. Proficient authors know how to write content, and how to weave the words together so that they accomplish the goal of getting read and of getting ranked well of search engines.
One cannot over emphasize this point. Content is king! Never forget it, less ye be banished from the kingdom of Top-Ten land.