Startups needs to think twice when they decide to use a .io domain.
.io domains aren't top level domains like .com, .org, or .net. They're ccTLDs - country specific domains - like .co.uk, .us, or .com.au. Io is the local domain for the Indian Ocean states. Unlike the TLDs, and a handful of the early ccTLDs, Google doesn't treat .io as a global domain - it treats them as domains specific to the Indian Ocean. This means you're immediately at a disadvantage at being found by your target market via a google search (unless they're specifically searching for your brand).
So while you're more likely to get a common-word .io domain, and they have the obvious relation with technology, if your start up is going to be relying on search engine traffic or might be dealing in a slightly grey area, you should probably just save yourself the bother and go for getX.com or Xapp.com, where X is your website name.