The very question of whether there is a penalty or not is something that continues to be debated. If you are running a website and are not so technically or SEO inclined and have called in a professional, it’s a fair bet that he or she would have mentioned the duplicate content penalty, and in some cases, might have scared you to death about the penalty (getting to a higher position on Google Search is so hard, nobody wants to suffer getting to a lower position or even being removed from the index).
But it you were to do some research, you would find that the duplicate content penalty is something that is more feared than it is real (with the exception being if the Google search algorithm determined that you are doing so wilfully to try to manipulate search engine rankings – at which point the wrath of God will come down on you). So, for example, I will give you 2 cases – one of which is duplicate content, and the other is both duplicate content and copyright infringement; both are from people I know (but will not mention any names).
Case 1: The person thought he will be smart. He had 2 different blogs on subjects that were separate and yet not very different. After a lot of content had been generated, he decided to combine these 2 blogs into a new blog (while retaining the 2 original blogs as well). So, after this manipulation, he had 2 original blogs and one new blog that just had the content of the 2 original blogs (every new content was effectively copied into 2 blogs). This in my opinion was a direct manipulation of the search engine indexing, trying to ensure that more people saw these blogs (whether the original ones or the new combined one). This went on for some time, for some months, and one day he received a notice in his Google Webmasters space which told him that this seemed like an effort to manipulate search engine rankings, and was a deliberate effort. This would impact his search engine rankings (and in fact, it seemed like it already had). In a state of panic, he removed the new combined blog altogether and tried to ensure that he added a lot more new content to the 2 original blogs and kept on monitoring his position in the Google Search Engine rankings. It took a few months, but finally it seemed to him that Google had forgiven him, and his ranking seemed to be back to its original self.
Case 2: Selling items through the Amazon Affiliate program seemed like a good deal. After all, if you are able to see items worth $100, you can get upto 5-7% return back, which is not a bad deal if you are able to get volumes. So, what did the person decide to do ? He would mine Google’s listing of top ranked items in different categories, and write about them with an affiliate link for people to click to, purchase and then make money (that’s the way it works, but it is not so simple as all that and the conversion rates can be pretty low). But, in addition to picking up ideas from Amazon about top selling items, the person decided to take a short cut and actually copy some content from Amazon for those items and splice them within his own content. It seemed to be working well for some time, and some affiliate money even started coming in, and then one day, everything stopped. The blog had been hosted on Blogspot (owned by Google), and one day the blog stopped becoming accessible. In spite of making efforts to contact Google and so on, it was clear that the blog was not coming back and had been locked.
These are extreme cases. But what typically happens is when the same content is noted on multiple locations, Google does not apply a draconian penalty. There is content copied all over the world, newspaper columns are syndicated to other newspapers all over the world, if there was a penalty, the newspaper sites would not be doing something like this. Instead, what happens is that the algorithm used inside the search engine figures out which is the site or link that seems to be the original and will pick that up to show at a higher level in the search engine. Which of course does not mean that you should not be trying to help the search engine. Suppose you are trying to sell on Print on Demand sites where the same design is used on wallets, caps, clothes, postcards, and others, a bit of effort would help. When using the same design, try to ensure that the description of each such product is different, even if the theme is the same and wording changes. This will ensure that search engines see them as individual products and do a better indexing and ranking of them.
Updated with respect to the various plugins and the themes being used on the site. It may seem something that seems important, but it cannot be emphasized enough about how important this particular procedure is. Very recently I had a friend lose his site (in fact, lose multiple sites) because one of the sites had not had its plugins updated to the most recent version. What happened was that one of the sites which did not have its plugins updated to the latest version got hacked. The specific plugin had a security hole that had been diagnosed some months back and a fix was also available through an updated version of the plugin, but since the plugin had not been updated, it was hacked. This hack enabled the hacker to get through to the base level of the site, which allowed the hacker to access the other sites as well (since they were all hosted on the same server as part of the same hosting package). For people who have multiple sites, it makes sense to ensure that all your sites are updated to the latest version for plugins, for the WordPress version, and for themes.
There are many security plugins available for WordPress that send out emails whenever they detect a newer version of a plugin, and maintaining and upgrading these components of the site should be part of the overall time budget for running the sites (it really does not take too much time to do it, and the effort involved should the sites get hacked is tremendous). I use a plugin called Wordfence Security (there is a free version and a paid version of this plugin), which ensures that I am aware of any potential problems on the sites. I have had a hack of my sites some years back, and hence am very careful now to ensure that my sites always remains updated. As a part of this, there is also a need to ensure an automatic backup program that will backup all the posts on a periodic bases should the worst come to happen, i.e, because of a hack, the contents of the site are totally lost.
Wordpress has also made this much more easy, with an automatic way to do this. Suppose you get an option where you have a configuration option to do an automatic download and installation of these plugins, in such a way that when the system knows that a newer version of a plugin is available, it will, after some time, do an automatic update of the plugin. This system runs through the use of the Jetpack plugin; this plugin has an option called ‘Automatic Updates’ which needs to connect to WordPress.com (where you need to have an account, or create one if you don’t have one). There, the plugins that you have on your site are listed, and you can select to enable the Autoupdates option for whichever plugin you want (I have done this for all plugins). You need to do this for all the sites that you have that are hosted on WordPress. It is a one time effort, but well worth it.
It would seem like many of the posts that I am doing talk about normal day to day stuff, stuff that you would consider as something that you would normally do. And yet, you would be wrong. It is so easy to ignore what is going on in the various services that you use, until you start seeing an impact, and that can be a killer. It is so easy to get stuck in the regular pattern of whatever you are doing with a service that you really are not attuned with what is ongoing (especially changes, whether they are minor until they start accumulating, or when a rapid big change happens all at once), and then you find your revenue and profit taking a hit. You really don’t want to be in such a position, right ? Well, then pay attention to this example and see where not staying on top can really hurt.
A service that allows you to use your photos / patterns / slogans for various photo creations can help provide some extra revenue, and there is one such service called Zazzle. So, for example, you have a funny slogan about Donald Trump (to cover both bases, you have another slogan about Hillary Clinton), and you think that people might want to sport caps or clothes with that slogan on it. Well, you can use that slogan on various clothes and even other stuff on your own store in Zazzle and hope to sell your stuff there. It takes time to catch on, you have to do publicity, you have to create a large number of products so that you start showing up in searches (both on the site and in Google), and you can literally create hundreds of household items, sporting items, phone cases, whatever, in a few minutes of work and can even add flourishes or further tweaks to the design. So, once you get into the thousands of products range, you can start making money. Sweet, right ?
However, there was a change in the basic groundwork beneath the feet. What this meant was, you could create hundreds of products all bearing the same slogan, all of them with their own web page. Guess the problem that gets created ? Zazzle found that its SEO effort was getting problematic, and the reason was – guess – duplicate descriptions across so many web pages. And many users had products in the hundreds of thousands range, which was something that was very worrying to Zazzle. For some time, they adviced creators to use unique descriptions on each product instead of the same one across products, but this has time problems. Finally, they implemented a hard solution (and maybe a bit arbitrary) where they decided that no creator will have more than 100,000 items, and products that exceed this number will no longer be live pages (there was a set of criteria to determine which of the products will be live and which will be off).
Now, for somebody who uses Zazzle as another service, they might have ignored most of this (almost all of this discussion and details happened on the forum site), until one day they logged in and found that out of their 500,000 products, more than 4/5th have been disabled and only 100,000 remain live. Now, the discussion on what will happen was there on the forums for some time now, and yet only those who have been following the discussion or considered it seriously would have tried to make an alternate strategy to work around this change instead of being faced with a situation which was decidedly problematic, and at the minimum, would take a fair amount of effort to handle.
Moral of the story being that you cannot just keep on making money off a service, you need to be aware of possible changes and figure out how it impacts you. This is true for strategies dealing with SEO, and many other strategies as well.