I wish I could have posted everyday for my first year, but it hasn't been possible for me. But even with less frequent posting, I do find the feedback on WIW posts to be enormously helpful.
I think by posting fairly regularly it has helped the forum members and Angie get a handle on my developing style, so that their suggestions hit the mark more often than not. They know what I already have in the closet and can suggest pairings I might not have considered, and they know what I'm aiming for, so they don't make as many "nice but useless" suggestions. Those KILLER ratings from Angie are priceless because you can then analyse the look afterwards and consider what its elements are. Also, the compliments really help to lift a person's mood!
I also find K/R threads extremely helpful, and "try on" threads as well. There, people are much more critical (in a good way) and so the threads serve a different purpose.
I must admit that my WIWs are usually of my "going out" outfits. Even if the going out is casual -- shopping, lunch in town. Sometimes I'll also post if I'm just trying a fun new combination, or I have a new item that I am dying to show off.
Lately I have also been trying to take daily work-at-hom photos -- even when I'm not going anywhere other than the gym. Because many of my outfits are repeats or are sort of boring in themselves I don't post these. But I'm hoping to collect a bunch of them and post them together as a sort of documentary, and for ideas going forward. What do I REALLY wear? What does that tell me about my actual needs? I learned a lot from Krista and Ingunn and Jayne on this. They kept records just for themselves and were able to make some excellent buying decisions as a result. I think you've been doing this as well?
Moving forward, I aim to do what Sveta does and post weekly WIWs. I got a tripod for Christmas so I won't always have to involve my daughter in the process if I don't want.
If nothing else, knowing that you are going to take a photo forces you to up your style game a bit. No staying in PJs all day!