"untapped by" is a correct phrase and can be used in written English.
It is typically used to indicate something that has not yet been used or taken advantage of. Example: The potential of the market in the developing countries remains largely untapped by multinational corporations.
H.Bloom targets a different demographic, however, and it's one left mostly untapped by Internet-based services.
Items are usually better priced, and untapped by city-dwelling fashionistas.
But Harry Potter has also crept into the grown-up imagination and filled a place untapped by adult fiction.
Perry's work was distinct in its blend of traditional theatre with African American Southern entertainment, which had been largely untapped by larger commercial enterprises.
Theatergoers are considered affluent, educated and largely untapped by marketers, and the 11 theaters collectively draw more than 3 million people a year.
The imprint is widely viewed to have had success with genre fiction in translation, a market that, crime aside, has been largely untapped by other publishers.
The debate continues a longstanding argument in the party over whether to move to the center to woo the independent voters who have decided recent close contests or try to energize untapped constituencies by railing against the status quo.
The potential for untapped revenue by applying great designs to your website is tremendous.
Since it's a relatively untapped market by other retailers, Torrid's appeal is expected to fuel earnings and sales growth for Hot Topic, while it extends its store base.
"Deep biosphere fungi are an untapped resource by the pharmaceutical industry".
Finally, despite the variety of current prediction methods, some aspects of disorder remain untapped, demonstrated by the observation that if a new experimental technique for identifying disorder comes along, existing methods fail impressively (GT Montelione, unpublished).
