If you want more clients for your business, a blog acts as a lead generation tool. Once you’ve driven people back to your blog you can invite those that are ‘very interested’ to sign up for a newsletter or email list. Once on your list, that’s where the sales take place.
Beyond simply asking people to sign up, you can offer incentives to attract the right sort of people. If you run a marketing agency, offer a free report on ‘Tips on Choosing a Marketing Agency’. If you offer PR training, give people to chance to sign up for a short course on PR. What incentive could you offer that will attract people who might later on buy from your business?