[cicero]

It is certainly viable. I follow an interesting group of users and unfollow anyone who becomes problematic. There are some "Promoted" tweets that are essentially ads, but they are easy to ignore if not interesting.

[Thlom]

I don't think I see any ads using Tweetbot. I may also miss some features, but don't really care about that. I like that my Twitter feed is just a stream of tweets.

[gideonparanoid]

I've found that with blocking every account I see a promoted tweet from, I barely see any any more.