As the author herself readily admits, she is a regular woman - not beset by any outlandish challenges or misfortune - trying to be as happy as she can be. She has neither the opportunity nor inclination to do something extreme, like travel around the world or go live in a yurt in her backyard, so she has to make do with what is in front of her. So far, so good.
She decides to tackle her project in a very methodical way and sets herself a challenge for every month. This is where it gets a little exhausting. Gretchen Rubin puts herself through a seemingly unending list of tasks to find the happiness within, ranging from the sensible (clearing clutter) to the bizarre (randomly buying three new magazines every week and forcing herself to read them all). She ploughs through stacks of happiness literature and the book is sprinkled with various quotes and snippets from her research and her own "great truths". Though she never pretends to be writing a scientific work, the avalanche of random two line quotes is a bit underwhelming.
I do applaud her courage for showing a relatively unattractive side of herself and daring to question her own behaviour. I would have been interested to learn more about her career change from a lawyer to a writer, which is not something that's included in the book as it is something that happened before she wrote it.
In summary, am not as blown away as some reviewers seem to be but she makes a few useful discoveries along the way and encourages you to think about your own life, so it could be worth reading just for that.