General Antonyms:
* Broad: If you're talking about a niche market, the opposite would be a broad market.
* Mainstream: This implies something popular and widely accepted, the opposite of a specialized niche.
* General: This emphasizes something encompassing a wide range of things, unlike a niche that focuses on a specific area.
* Universal: This refers to something applicable to everyone, as opposed to a niche that caters to a specific group.
Other Possibilities:
* Mass: This can be used as an antonym for a niche market.
* Widespread: This suggests something that's prevalent across many areas, opposite to a niche that's more confined.
Example:
"The company's niche product was so successful that it soon became mainstream."
It's important to choose the antonym that best fits the specific context of your sentence.