Complex sentence: Beginning in 1980 with the Iowa Department of Education, 5,000 school districts around the world purchased site licenses for MECC software; the "Institutional Membership" business became so profitable that state subsidies for MECC ended.
Split into simpler sentences: Beginning in 1980 with the Iowa Department of Education, 5,000 school districts around the world purchased site licenses for MECC software. The "Institutional Membership" business became so profitable that state subsidies for MECC ended.