Test the fit with the main brand's promise
Ask whether the acquired business reinforces the main brand's central proposition or makes that proposition harder to explain. The Google and Yahoo! comparison illustrates the distinction: Yahoo! diversified until people no longer understood what it represented, while Google remained closely associated with search. Google kept acquired brands separate and grouped home-grown projects under Alphabet, with activities carrying the Google name largely helping consumers search or advertisers capitalise on search behaviour. Use that logic as a clarity test for an acquisition: can customers understand why the acquired business belongs under the established name? If explaining the connection requires stretching the main brand's promise, keeping the acquired brand separate may preserve a clearer proposition.
Sources: Strategy is complex, but winning brands keep it simple