In addition to the answers in this thread, you might find some answers in these past threads:

• Why did Albania and Bosnia become majority Muslim countries but the other Balkan countries under Ottoman rule did not?

• Why, out of all the regions in the Balkans, were Albania and Bosnia the only regions which converted to Islam?

• Why did Bosnia and Albania become Muslim, but not Greece?

edit: /u/yodatsracist /u/kaisermatias /u/UrbisPreturbis