I haven't pledged any money to WTTW, WYCC, or WYIN since I barely get by financially. I don't know if I'll send in any money for their pledge drives, but I do show interest in buying certain programming directly from the station. I like some of the documentaries that WTTW produces specifically for their pledge drives, like stuff about Chicago & the suburbs. The nice thing about WTTW since the DTV transition, is that if programming is interrupted on 11.1 for pledge drives, WTTW Prime on 11.2 doesn't get affected, & some programming gets moved to WTTW Prime during pledge drives. They also from time to time run the pledge drives on WTTW Prime & keep their regular schedule on WTTW 11, 11.1.
WYIN runs pledge drive programming every night just to keep the station on the air, or they'd just sign off at night (which they haven't done since 2007 or 2008, when they decided to go 24 hours). They also air some pledge drive programs during the daytime too. I however hate that their pledge drives have people who don't actually work for the station, & instead, the people who interrupt the programs only mention public television in generic terms. They never mention the actual station. These type of pledge drives are made for PBS stations that don't want to take the time to interrupt the programming themselves. The actual station like WYIN has a blue bar at the bottom of the screen with their toll free number, station identification, & the station's website to go to to pledge online.
Out of the 3 Chicago PBS stations, I'd probably pledge my money to WYCC first, since they rarely run any actual pledge programming. Almost every time between programming, they have someone from the station who asks people to pledge money for their programming, & keep it brief. Most gifts people get from WYCC is usually something like dinner for 2 at an area restaurant, or to see a movie or play. It's typically something to support a local business, rather than something material, like other PBS stations. WYCC does offer something materialistic on occasion when they do have a pledge drive. Blue Man Group is the one pledge drive program that's most likely to me shown.