With 925 active clients extracted from data warehouse, the market segments are clarified with the support of several clustering algorithms for selection and preprocessing data. Some of these algorithms are RFM and Customer Value Matrix. Findings are quite important contribution to effective marketing and sales strategies, not only to avoid occurred spams but also to limit churn risk and maintain customer retention. Also it brings a tangible effect on operation results by allowing higher percentage opportunities for company sales revenue. Company spends less time on less profitable opportunities and more on the most successful sections to ultimately increase revenues.