You can do nearly everything "the computing cloud" offers without it : just use servers, install your services on it, manage it, invest in more servers/ more powerfull servers if needed... Cloud computing is not a brand new invention, it's just delegating the server and services management to others... Whereas, a century ago, electricity was actually an essential input.
... and have the staff with experience and resources to keep them running. These days, UPS maintenance is sourced out to the cheapest bidder and testing is infrequent, with the predictable result of shit hitting the fan at the exactly worst time.
Then I can imagine SAAS companies offering discounts if your API requests originate from AWS cloud.
Maybe even Amazon prime members will get free bandwidth from their home internet connections into and out of AWS.
At some point, the whole lot becomes a walled garden, and being outside it is more expensive if you need to use services that are inside.
Although this idea makes practical sense, from a financial standpoint I don't think there will be enough incentive.
Bandwidth savings in infra will represent <1% savings relative to the SaaS/API price.