An ellipsis (plural ellipses) has one conventionally standard purpose: It signals that the writer has omitted something from a quotation.
An ellipsis looks like this: [ . . . ] There are spaces before and after the ellipsis, and there are spaces between the periods comprising the ellipsis. For example, I am omitting a portion of the following sentence:
Obama baffles observers . . . because he’s an ideologue and a pragmatist all at once. [NY Times]
In some formats, particularly in web writing, the internal spaces have disappeared from ellipses. Many news websites have article teasers like this:
Health care reform was supposed to be President Obama’s overriding issue heading into the new year, but …
In informal writing on the web, the ellipsis has become a catch-all punctuation mark to replace colons, semicolons, em-dashes, commas, and even periods—for example:
And speaking of Napolitano’s abysmal performance over the weekend… where’s Hillary? [Althouse]
I quit watching cnn because of this bias…it’s propaganda tv to me it’s not even news. [Glenn Sacks]
Let the good times roll … [Dirt Road Heaven]
This type of ellipsis use is common on blogs and in web comment boards. But, to the credit of most high-profile news websites (with some ugly exceptions), it hasn’t caught on where high editorial standards are enforced.
