I have to start with an observation about complaints what occur occasionally on stock photography sites: "Somebody stoled my keywords - please, stop it!", "How can I prevent others from copying my keywords?", "Keywords copied - is it right?!"
Well, from legal wiewpoint - there's no law about words copyright. "Titles, names, short phrases, and slogans; familiar symbols or designs; mere variations of typographic ornamentation, lettering, or coloring; mere listings of ingredients or contents" are NOT eligible for federal copyright protection, stands on webpage of the U.S. Copyright Office. (http://www.copyright.gov
You can't own keywords, you can't copyright them, so there's no legal base for punish people, who copy keywords. From ethical viewpoint - is it right thing to do? Everyone can decide. But let's consider another viewpoint. Buyers viewpoint.
If I would be a buyer, I would be very happy, if same type of images have similar keywords. So I could type only one word or few words into search field and get all possible results on that topic. And I could quickly select my image. It would be very frustrating to think out all kind of synonyms to find all good images on the subject. Kinda sad, if I don't get a good image among results only because the seller missed out a vital keyword.
So, if we are thinking from buyers side, the more unity we have in keywords, the better it is and the more happier buyers are. The more happier buyers are, the better reputation site has. The better reputation site has, the more buyers we have. The more buyers we have, the more happier we are. So, there's a conclusion - IT'S NOT BAD AT ALL TO COPY KEYWORDS. Of course only when they are RIGHT and RELEVANT keywords.
But - if we are thinking like sellers, who hate competition and want only OUR images into search results, then of course we protect jealously our rights on words. But the point is - if we have good images and buyer get them on search results, then he definitely notice them and buys them, but if we have average images, but good keywords, and buyer gets only our images on search results (because creators of good images on this topic don't speak English or are not clever enough to think up those keywords like ours), then maybe buyer buys our average image, and we are happy, but it could be the last purchase of that buyer on this site, because buyer gets impression, that we have only average images online. And maybe he decides not to be returning customer.
So maybe it's better, that we could have similar keywords with others, buyer gets wider selection in search results and is not frustrated about thinking up synonyms, and maybe this time he buys another good image and not our, but he is happy about quality, and returns to buy another image about another topic, about which WE have a good image. Wouldn't it be much better? Buyer returns, site stays in business, and we have opportunity to improve our portfolios?
We are not here because we have great verbal skills, we are here because of our images. And buyers are because of our images. So really - all keywords are irrelevant... only images matter.
Keywords are mere means for buyers to find images THEY need, and our job is to provide those images, and use such keywords, what help buyers find what THEY need. That's stock industry about.
So, I really think that copying keywords is a good thing, it's good for site and it's good for buyers, and everybody can copy my keywords, if they find them good. I really don't mind. But please, copy only relevant ones, cause I'm also eager to report all irrelevant keywords, what disturb my searches on site. I want Search Engine to work perfectly, and do what I can to improve its functioning. It's the heart of stock industry.
PS: OK, after reading some feedback, I correct some things what I previously said and take back my words "everybody can copy my keywords". I still wouldn't be mind, but I can see, it's not acceptable on Dreamstime. So, please don't do it. Though I still think it could be a good thing for buyers and site in the long run.