Finances. You need to be good at quick math and be able to make quick decisions. You have to be careful how much you pay for a book, and then keep careful track of the expenses involved in selling it. For instance, when you sell on a website, they’ll take a commission from the sale. In addition, some sites, like eBay, will charge you a listing fee for each book. If you request that your money be deposited via PayPal, then you’ll be charged a transaction fee per book. If you’re not careful, the fees will quickly negate your profits.
Find a profitable niche: We’ve talked about this a lot. But, where are you most comfortable. What niche do your skills, values, and interests intersect? Do you have 10 years of experience as a technical writer? Do you have long-standing PR relationships that’ll be invaluable in helping startups launch a successful crowdfunding campaign? Determine what makes your value unique, and lean heavily on showcasing that strength to your potential clients.