Google "failures" can have millions of happy users... if google ejected 10m users, and you can gain say 1/10th of those, 1m, and even 10% paying $5/month that's $500k/month of gross income. Depending on your needs, a well designed system to support 1m users or so could be done under $50-100k/month, leaving $400k/month for staff and profit.

While it may not make sense at Google Scale, it can absolutely make sense for a small business spinoff.