MBA: Abbreviation for master of business arts. No periods.

metadata (n.): One word.

news feed (n.): Two words, lowercase.

news release: Use instead of “press release” whenever possible.

nonprofit: One word.

OK (n., v., adv.): To be used interchangeably with okay. Do not use variations such as Ok and o.k., which are incorrect.

opt-in (n., adj.), opt in (v.): Hyphenated as a noun or an adjective. Two words as a verb. (Examples: The opt-in has been disabled. To receive electronic statements, you must opt in.)

page view: Two words. The viewing of a web page by one visitor. (Example: Advertisers consider how many page views a site receives when deciding where and how to advertise.)

pay-per-click: Hyphenated (abbreviation: PPC).

plugin (n., adj.), plug in (v.): One word when used as a noun or adjective. Two words when used as a verb. (Examples: She needed to plug in her laptop to charge it. She downloaded a plugin for her web browser.)

podcast: One word.

pop-up (n., adj.), pop up (v.): Note hyphen when used as a noun or adjective. Not popup.
Two words when used as a verb. (Example: Get rid of pop-ups before they pop up. Stop pop-up ads from ever annoying you again.)

PPC: Abbreviation for pay-per-click.

real-time (adj.), real time (n.):
retweet: Lowercase, not hyphenated.

RSS: Acronym for Really Simple Syndication. All capitals. Abbreviation is always acceptable, but avoid using RSS on its own, since few people know what it means. Use news feed, RSS news feed, or RSS reader as appropriate.

salesperson, salespeople:
screen capture: Two words.

screencast: One word.

screen name: Two words.

screenshot: One word.

SEO: Abbreviation for search engine optimization.

setup (n., adj.), set up (v.): One word when used as a noun or an adjective. Two words when used as a verb. (Examples: Set up your Yahoo! store. Check your Yahoo! store setup. Your setup fee has been waived.)

sign-in (n., adj.); sign in, sign in to (v.): As a noun or an adjective, it’s hyphenated. As a verb, it’s two words, which may be followed by the preposition to. (Examples: All visitors must sign in on the sign-in page. Visitors can sign in to Yahoo! Mail automatically. Choose your preferences for sign-in and security.)