This article is posted from the St. Louis Post Dispatch and can be accessed here. http://www.stltoday.com/business/local/relationship-with-apple-customers-key-to-clayton-firm-s-success/article_0822ec87-c475-5602-ab11-d20596f2e4a0.html Matina Koronis-Koester is president and founder of Digital Partners Inc. in Clayton. The 20-year-old firm sells and services products made by a wide range of technology companies, including Apple, IBM, Hewlett-Packard and Cisco. Koronis-Koester was three years out of…