It got off to a rough start, but the Oprah Winfrey Network is finally starting to see the high ratings investors expected would come with the talk show queen.

August marked OWN's seventh consecutive month of ratings growth, with viewership among women aged 25 to 54 up by 39 percent during prime time and 45 percent over the entire day.

Part of the boost comes from Winfrey's high-profile interviews and her continuing ability to nab exclusives even without the enormous ratings of her daytime "Oprah Winfrey Show."

Her new program "Oprah's Next Chapter" has seen big ratings for some of her most buzzworthy guests. Her Aug. 19 interview with Rihanna, where the teary-eyed pop star dished about ex-boyfriend Chris Brown, drew 2.5 million viewers, the show's biggest audience since Winfrey brought 3.5 million people to OWN for a March 11 episode with Whitney Houston's family following the R&B star's death.

"Next Chapter" has also scored big with interviews featuring the Kardashian family (1.1 million and 1.2 million viewers for each of two parts), Olympian Gabby Douglas (931,000 viewers) and Paris Jackson and 50 Cent (911,000 viewers).

The ratings boost over the last few months means OWN is now a top 40 cable network, more popular than other established channels like CNN, BBC American and Style.

In July, Discovery CEO David Zaslav said OWN ratings were up "well over 50 percent" in its key demographic, and the network is expected to turn a profit by late 2013.

Winfrey has publicly acknowledged the difficulties of building a network under the spotlight that comes with being Oprah, calling it "the climb of my life." But she was optimistic at a presentation for advertisers in April.

"With our restructuring and right-sizing and getting into the sauce of what needs to happen every day, I feel like I can at least now see the summit," she said.

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