It very much depends on the market. This is the reason why Seagate and Western Digital aren’t big names in the SSD market. They dominated the mechanical drive market for years (and still do!) but by the time SSDs were worth pursuing, other companies were light years ahead of them.
Google isn’t really in the business of filling small niches. That’s why they kill so many products that have small but passionate user bases. It’s just not worth their time and money so they shut the products down. This is why I can’t see them trying to start with a small social media niche and slowly expand to a bigger market. It’s a great idea; but seems to go against everything they do.
That's because HDDs and SSDs are actually very different on the inside. They do roughly the same, but just because a company is good at manufacturing HDDs does not mean that it can also produce good SSDs.
Google isn’t really in the business of filling small niches. That’s why they kill so many products that have small but passionate user bases. It’s just not worth their time and money so they shut the products down. This is why I can’t see them trying to start with a small social media niche and slowly expand to a bigger market. It’s a great idea; but seems to go against everything they do.