Clever wordplay ("zip" + "city") with positive connotations that could suit many uses. For instance, a company that manufactures and designs zips.
Also, a commuter app, that helps people move around a city quickly. It could suit a company that created a travel app (i.e. something helping people understand and navigate a city).
The word "zipacity" contains eight letters and four syllables. Four syllable names are used by established brands like ESPN, Airbnb and Panasonic.
Zipacity.com is a .com domain. Dot com domains are the most valuable domain extension in the world, used by famous websites like twitter.com. A .com is the first thing people think of when they think of a website.
This domain was first registered in April 2013. Older domains have an advantage when ranking in search engines.