Short term everybodies homes were ruined and destroyed, peoples lives were lost and people all over the Roman Empire lost a provider meaning other cities had to step up to accomodate the people of Pompeii. Other cities also had to provide what Pompeii did along with what their city already provided.
Long term it provided a huge surprise and tourist attractiion when Pompeii was found again. Pompeii had been forgotten before its acidental rediscovery in 1749. After that Pompeii became a huge tourist attraction; in 2008 2.6 million people visited Pompeii! It also provided a very intresting insight into a roman city seeing as it had been preserved so well in the hot mud,pumice and ash.