Yes, the OP posted only to attract snake oil merchants... in fact OP is associated with a specific snake oil merchant who recommended their product shortly after.... so partner came and was gone less than 2 hours later when i saw it and deleted. I debated whether to delete or leave the original message but figured real people might learn from it.. and if it attracts too many spammers, I'll lock it later.
Honestly, the ost to pst (and other formats to pst) people are the absolute worst spammers. They'll post a question as someone else then answer it. Many are just reselling other companies products. In one thread, i delete the spam, then posted an answer - I named the company and said they spammers and not to be trusted. They came back a few days later and posted again! Clearly either did not read before posting or did not understand English. Sad part is, these scammers make everyone less trustful of people from their country.
As for the need to convert ost to pst, the biggest reason is because ost only work with the account and profile that created them. if you need to access data in an orphaned ost, you need to convert to pst. This was most common with people leaving companies who had personal content in their mailbox and a laptop - they deleted the company account and lost their contacts. Now its needed by the lucky few who have an imap account and put stuff in the this computer only folders *and* made a backup of the ost file.
Convert an Offline File (.ost) to a Personal File (.pst)
Scanpost is no longer recommended - since its a copy of the server, just rename the ost and resync.
The only issue is with imap accounts in outlook 2013 and newer- they use an ost file and can store calendar & contacts, which are not backed up or synced anywhere.... and the ost is deleted when the account is deleted. Not pretty.