Diana Gabaldon is having something of a George R.R. Martin moment. The eighth book in her hugely popular Outlander series, Written in My Own Heart’s Blood, bowed on June 10 and, according to Random House imprint Delacorte Press, which publishes the series, sold almost 200,000 copies its first day available. In print, the novel outsold Hillary Clinton’s memoir, Hard Choices—which debuted the same week—by an 89,000 to 85,000 count, according to Nielsen BookScan. Heart’s Blood, as well as Gabaldon’s backlist, should benefit some more when Outlander premieres August 9 on Starz.

Like Martin’s book series, A Song of Ice and Fire, which was a huge bestseller with a dedicated following well before it became the basis of the HBO series Game of Thrones, Outlander has an almost cultish fan base. Last month, Random House hosted an Outlander Retreat in Seattle, which drew over 500 fans; tickets for the event, the publisher noted, sold out in under six minutes. Because of the similarities between A Song of Ice and Fire and Outlander—as two fantasy/historical fiction series with matching cable TV miniseries—it’s hard to avoid comparing Gabaldon to Martin these days. And Random House, understandably, is hoping Outlander the TV series turns Outlander the book series into a household name, the way Game of Thrones did for A Song of Ice and Fire.

“It’s not some new phenomenon,” explained Ballantine Bantam Dell executive v-p and publisher Libby McGuire, speaking about Outlander, which, according to RH, has 25 million copies in print worldwide. “It’s just that only people who knew about it knew about it,” she said. When talking about what has happened to Martin’s readership, post-HBO, McGuire is hopeful but remains realistic. “If we even get a portion of the Game of Thrones [effect] that’s great.”

The first Outlander book came out in 1991—Delacorte has always been its publisher—and grew out of a manuscript that was supposed to be a “practice attempt” at novel-writing for its author. Gabaldon, who has a Ph.D. in quantitative behavioral ecology, was a university professor at the time, and had been working on the book in her spare time.

The story line follows a married Englishwoman named Claire who, just after WWII, is sent back in time to 18th-century Scotland. (Claire’s on a vacation in the Scottish Highlands when she slips through the time-space loophole.) After landing in Scotland in the 1740s, she falls for a clansman named Jamie Fraser, and the series charts her attempts to get back to her husband, as well as her adventures/love affair with Mr. Fraser.

Although Outlander has historically drawn a larger female readership than male, given its emphasis on Claire and Jamie’s through-the-ages romance, McGuire said men have also come to the books. Steeped in history, Outlander, McGuire said confidently, “appeals to men.” Although McGuire said that Outlander features less sex and violence than Martin’s series, the hope is that its similar blend of fantasy and historical fiction will draw significant viewers the way Game of Thrones has.

RH said Gabaldon has also been as deeply involved in the Starz series as Martin has been for Thrones, visiting the set and approving many aspects of the show. (The Starz version is based on the first book of the series.) For its part Starz, which is less established in the cable TV series game than HBO, has already committed to air one full season, breaking the show up into two eight-episode blocks. RH, for its part, published a TV tie-in edition to book one that was released on July 1.

McGuire said that Gabaldon, who is still writing the series, knows the entire story arc, if not “how many books it will take to get there.” For now she, her fans, and her publisher, are looking forward to the TV version. For Random House, the show marks a chance to hook those who don’t already know about the series. And McGuire is confident they will be hooked: “Everyone who reads that first book keeps reading.”