Because enjoying a small piece each day is far better than bingeing through the whole box of tricks in a single session.

Marketing and promotion needs to be a habit that you do, almost without thinking, each day. A great big advertising push followed by nothing for months is particularly useless on the web, where everything gets out of date so fast.

Marketing works best when it's something you actually enjoy, rather than a chore you have to force yourself to perform. I suppose that should be obvious, but all the time I hear writers and designers complain that they want to do their creative work, and only put time into marketing because it's necessary. Many people even seem to see their hatred of marketing as a badge of creative authenticity.

Well, if you want to loathe doing your marketing and communications that's up to you. But as it's got to be done, it's surely better all round to make sure that it's an activity you actually enjoy.
This is more likely when:

• It feels authentic. No-one enjoys either doing or receiving "hard sell". Just do the kind of promos that you honestly do relate to and that feel like the real you, even if it seems quite gentle stuff compared to the blare of some of the big brands.
• It's interesting. I'm not suggesting you jump all over the place and try everything. But sometimes doing something you haven't done before is more fun than "same old, same old". Today I made my first ever Facebook ad. A modest little thing to be sure (there's not a whole lot you can do visually with a Facebook ad - well, maybe I haven't come up with anything more dramatic yet) but I'm genuinely excited to see how it does. It's energised me.
  
• It's not too much of a strain. Don't force it to the point where it's exhausting. Do something small each day and go on to some other activity (like your main design/writing/music/art work) once the marketing stuff stops being fun.
• It's creative. You don't have to ape the big brands to be an effective marketeer. In fact it's usually much better if you do something that's fresher, different and more "you". Find a tone or a style or a format that isn't the same as everyone else's. Use your imagination and your ability to make something new and distinct.