The English idiomatic phrase “a dime a dozen” is used to refer to something that the speaker feels is extremely common, and thus not very valuable. This phrase is used quite a bit for any object, whether simple or abstract, that is thought to be essentially worthless because there is so much of it on a market, or so much generally available in a community. This sort of statement about worth is part of a more colorful way of looking at valuations for business, personal finance, or for any other purpose.
In terms of its origin, word experts point out that the phrase “a dime a dozen” can only have been used after the beginning of the 19th century when the dime, 10 cent, coin was invented in the American economy. This is also an essentially American idiom based on the currency of the United States. People may use this phrase around the world, but it originated from relating objects to the worth of the dime, which was minted so excessively by the American government that it came to be of very low value as a collectible.
Any consumer good that is abundantly available can be said to be “a dime a dozen.” People can even use this phrase to refer to abstract items like talent. Here, the phrase can even apply to people. For example, someone might say that skilled web developers are a dime a dozen in a given commercial environment. This statement maintains that the talent of the individuals in question is not worth very much because there is so much competition within the field.
It’s important to note that the phrase “a dime a dozen” stands in contrast to another quintessentially American idiom that has a much newer origin. Over time, within this English-speaking society, the idea of an informal rating system gained presence within the general English lexicon. The most common form of this rating system started with one and ended with ten, making ten the most desirable rating available. From this comes the idiomatic use of the single word “dime,” as something that is rated at the top of a scale. Most often, this idiom is used for attractiveness for either the male or the female, where a very attractive man or woman can be said to be a “dime,” meaning a perfect ten in terms of attractiveness.