Everybody keeps saying the Sports Hub and WEEI are "neck and neck" but in reality (meaning advertising reality) that's not the case. WEEI used to be number one in Men 25-54 in the drives. By a lot. Not anymore. T&R are beating D&C in that demo and F&M rates higher than the Big Show. In men 18-49 and men 18-34 (the next generation of sports radio listeners) the differences are even more stark. Sure, being on a big FM signal helps, but content has a lot to do with it.
WEEI is staying "neck and neck" in the 6+ beauty contest for two main reasons. First, they have a sizable 55+ audience which pad overall numbers but doesn't help in the demos advertisers look for. Second, they have a politics heavy morning show (which really belongs on WRKO) attracting an audience that often doesn't listen to the station the rest of the day. Entercom has basically sacrificed 680 to keep WEEI afloat. Add in the huge Sox radio rights and the inflated contract to Ordway and you have a station that is in serious trouble.
Moving it to FM won't help much, since 98.5 is a much better signal than either 93.7 or 107.3/97.7. Entercom has to address the content issue, but due to their financial constraints they can't do it right. This "battle" will linger for awhile but 98.5 is poised for more sustained success in the long term.