A dispute over ad revenue may lead to the end of Rush Limbaugh's relationship with Cumulus Media. Reuters

More than 100 advertisers, including all technology sponsors except for LifeLock, have withdrawn their commercials from The Rush Limbaugh Show over the past five weeks.

The four-times-married but childless Limbaugh, 61, provoked the boycott after characterizing unmarried Georgetown Law School student Sandra Fluke, 30, as a slut and a prostitute after she testified before Congress on Feb. 23 on behalf of federal contraception funding.

Limbaugh, whose three-hour radio talk show claims as many as 20 million daily listeners, said his ad numbers are unaffected and denied he's anti-woman. He's continued his usual provocative style by claiming Monday that reaction to the shooting death of Trayvon Martin is doing more harm to the black community than anything else out there right now.

Martin is the 17-year-old Florida teenager killed on Feb. 26 by a man on community patrol in Sanford, Fla.

Limbaugh's initial remarks triggered an outcry from women's and liberal groups usually at odds with his rhetoric. In three days, most of his technology advertisers such as Carbonite (Nasdaq: CARB), the developer of PC backup systems; software management provider Citrix Systems (Nasdaq: CTXS) and online service provider AOL (NYSE: AOL) withdrew.

They were quickly followed by Netflix (Nasdaq: NFLX), (Nasdaq: STMP) and PolyCom (Nasdaq: PLCM) as well as Capital One (NYSE: COF), Deere (NYSE: DE), Allstate (NYSE: ALL), Sears Holdings (NYSE: SHLD) as well as private ProFlowers, LegalZoom, Sleep Number and Sleep Train

LifeLock Remains Loyal

Private LifeLock, of Tempe, Ariz., has remained. The company provides identity theft protection services. Among its directors is Tom Ridge, former Republican governor of Pennsylvania as well as the first secretary of homeland security under President George W. Bush.

Media Matters, a liberal advocacy group, as well as market researcher A.C. Nielsen (NYSE: NLSN), now report the dropped advertisers list continues to grow, although some confusion arises with companies with contracts on many of Limbaugh's 600 stations whose spots may or may not air during the broadcaster's showtimes.

The latest to leave include H&R Block (NYSE: HRB),, Fisher Nuts and Papa John's International (Nasdaq: PZZA). All left after March 20.

New Broadcast Challenger

Limbaugh's show is syndicated by Premiere Networks, which has responded to the criticism by telling radio stations to replace withdrawn commercials with other things. The move has also extended to advertisers on hourly newscasts that precede Limbaugh.

Premiere is owned by Clear Channel, now based in San Antonio. Clear Channel was taken private in a $20.6 billion buyout in 2008 led by Bain Capital and Thomas H. Lee Partners, two giants of the private equity sector. Republican presidential candidate Mitt Romney is the co-founder of Bain Capital and still receives funds from it, although he doesn't participate in management.

To compete with Limbaugh, rival Cumulus Media (Nasdaq: CMLS), which owns 570 stations, has been marketing a new show featuring conservative Mike Huckabee, 56, a former Republican governor of Arkansas and unsuccessful presidential candidate.

Cumulus announced in late March 180 stations will air Huckabee, who'll go mouth-to-mouth with Limbaugh at noon EDT, including on 40 of its own channels. Lew Dickey, Cumulus CEO, told the New York Times the show is being marketed as an alternative for economic reasons.

The Fox Connection

If the Huckabee show gains traction, Cumulus might be able to book stations that now air Limbaugh over time as their contracts run out.

Cumulus also plans to launch a radio show with Geraldo Rivera, already a fixture on News Corp.'s (NYSE: NWS) Fox Broadcasting, where Huckabee has long had a talk show.

Nielsen Media estimates Limbaugh's show brings in as much as $361 million annually. The broadcaster himself, No. 23 on the Forbes celebrity list, doesn't publish his finances but speaks about his lavish estate in Palm Beach, Fla., private jet and luxurious golf outings with friends to Hawaii and other venues.

Limbaugh has long boasted of his affection for technology, especially Apple (Nasdaq: AAPL) products. He has complained on the air that Apple has never advertised with him.

Cumulus shares fell 7 cents to $3.42 in midday trading Tuesday.