The phrase "a vast base of" is correct and usable in written English.
It can be used when referring to a large foundation or collection of something, such as data, resources, or support.
Example: "The organization has built a vast base of loyal customers over the years."
Alternatives: "a large pool of" or "an extensive collection of".
The thousands of clubs beyond this elite have very little resources, constituting a vast base of 'have-nots' in football's financial pyramid.
But beneath them are a handful of giant conglomerates that are struggling towards profits, a tier of middling banks with overexposure to risky assets, and a vast base of small banks in deep, deep trouble.
The siting here of the country's first new reactor in decades is no doubt in part because of the unique nature of the TVA, a New Deal-era government-controlled corporation with a vast base of municipal utilities and other large customers that buy its power.
Most will conclude that however meritorious Lincoln Chaffee's case for being elected America's 45th president is, he doesn't stand a chance, particularly against the Clinton political machine and its vast base of financial support -- and that this is a tragedy for Mr. Chaffee.
Moreover, Yahoo! has a key advantage over Google: because of its vast base of registered users (100m people use its e-mail, travel and other services) it is in a better position to tailor searches to users' needs.
To service its vast base of users, the company had to go back to investors repeatedly for money, ultimately requiring seven hundred million dollars.
Those who follow Alan's articles know that prior to his homerun successes with MarketStar, Mercato Partners venture capital, and his vast base of early-stage investments, he had experienced several entrepreneurial failures.
Those in large cities, like WNET in New York and WGBH in Boston, with vast bases of wealthy private and corporate contributors, are well on their way toward the changeover.
Welfare Inc. has a vast client base of consumers (taxpayers and their dependents), most of whom are also shareholders (voters), a large number of whom receive dividends (benefits).
Furthermore, YouTube already has a vast talent base of gaming superstars.
Titles like Farmville, Bejeweled and Cafe World, quickly drew in a vast user-base of female gamers, and even more elusively, older female gamers.
