In the September Arbitron ratings, covering the period from Aug. 20-Sept. 16, upstart 98.5 The Sports Hub (WBZ-FM) finished 17th overall in the market, receiving a 2.5 share and a 488,000 cumulative audience (or “cume’’). That is the number of listeners who tuned in at least once during a given time frame.

While it wasn’t a massive leap, it was a significant and encouraging improvement over the station’s debut numbers in the August book, when it earned a 0.6 share and a 136,800 cume.

Yet The Sports Hub’s growth did not make much of a dent in WEEI’s listenership. WEEI earned an overall 5.2 share in September, good for fifth in the market and up from 4.5 a month earlier, when it finished eighth overall. Its cume of 642,000 was up nearly 90,000 listeners, though WEEI’s overall numbers are bolstered in the summer by owning the broadcast rights to the Red Sox.

Mike Thomas, The Sports Hub’s program director, was reluctant to compare the fledgling station’s numbers with those of WEEI. Instead, he emphasized that The Sports Hub has made significant gains over the ratings of WBCN-FM 104.1, the legendary Boston rock station that went dark when The Sports Hub was launched. (In the CBS Radio-mandated shuffling, Mix 98.5 moved up the dial to take over the 104.1 spot.)

The sports radio competition, said Thomas, “is not our main focus right now. For any new radio station, it’s about the marathon, not the sprint. We want to do well in the marathon. We weren’t expecting that we were going to be tied with WEEI, which has been here for 20 years, right away. It’s going to take some time.’’

Thomas noted that The Sports Hub’s ratings among males 25-54 were up more than 40 percent (a 4.0 share compared with 2.8) over WBCN’s ratings during July, its final full month. They were up 26 percent with 18- to 49-year-olds (4.3 to 3.4).

“That the type of increase we’re looking for right now,’’ he said. “We want to perform better than WBCN was doing, and we are.’’

So are some of the specific programs. The “Toucher and Rich’’ morning show, the only major refugee from WBCN, saw its ratings climb 45 percent among men 25-54 and 49 percent for 18-49-year-olds compared to the show’s July ratings at its previous home. And the drive-time “Felger and Massarotti’’ show earned a 4.4 rating among 25-to-54-year-olds, up from the 3.6 rating WBCN earned in the time slot in July.

When Michael Felger, the brash co-host of “Felger and Massarotti,’’ was asked if he was satisfied with the progress in the ratings, he replied, “Ah, yeah. It’s a good start, and that’s what we’re looking for. I know everyone wants to play up the radio wars and all of that, but the goal is to keep growing and establish the station.

“I think that eventually we’d like to be a top 10 station in the 25-to-54, but it’s a gradual process. It’s not just that we’re a startup, or a dial shift, or a format change - we’re all of those things, and after all of that, we have to be very happy with where we are right now.’’

Especially given that Felger, who was hired to host the drive-time show on the neglected and now-defunct ESPN 890 when it debuted four years ago, knows what a hopeless cause can look like from the inside.

“Oh, this is not even close to that,’’ said Felger, noting that there were times at 890 when the listener interaction was so sparse that he wasn’t sure if anyone was listening. ESPN 890 never pulled higher than a 0.6 share.

“This is night and day,’’ Felger said. “This is a very encouraging situation, and the numbers today say as much.’’