The personality of a sales representative is of remarkable significance to suceeding in personal selling. His competency is therefore a presupposition of achieving success with this sort of sale. This issue was investigated on a group of commercial representatives (insurance service advisors) who work for an insurance company operating in the Slovak insurance market. The reason for studying this question was the fact that in spite of the company's effort to select qualified employees (sales representatives), there is a prevailing problem of unproportionally high external mobility (i.e. employees terminate the employment). The reasons for such mobility were studied and measures were proposed for stabilizing commercial agents to work at the analyzed insurance company.