SMB's need to mobilize their websites and add https encryption
Google's mobile-first indexing change will have the greatest impact on small-to-medium sized businesses. Enterprise companies have IT resources to make the necessary changes to mobilize their web properties. But SMB's struggle just to keep up with maintaining page rank through proper SEO and compelling content.
Google has also called for increased web security with encrypted (https) websites. In fact, website owners that don't install encryption on their web pages may experience user resistance. The Google Chrome browser, for example, will show an insecure site indicator on the left side of the URL bar. SMB's, again, need to allocate resources to secure their sites, especially for e-commerce applications. Securing email sign-up form or e-commerce cart pages won't do the job. All pages need encryption.
In the end, however, a mobile-first strategy, along with SSL encryption, will benefit website users and owners. The Internet harbors many dangers. But SMB and other website owners can both protect and enhance user engagement through mobile-friendly, protected sites.