Hm, that's an interesting question. Here are some tradeoffs I can think of:
- 2 extensions means the reviews get split between versions. So one extension might not have as good a reviews as the other meaning it gets found and installed less on the Chrome store. On the other hand, if one gets worse reviews then at least those reviews wouldn't affect the other as would be the case for just having one extension.
- If somehow the paid and free versions get marked as duplicates then they're both at risk.
- The two extensions wouldn't share data so a user would have to migrate all their data over if they upgraded to the paid version.
- I'd imagine that the more complicated install flow for having two extensions would mean a lower rate of people using the paid version.
Personally, I think I'd go with one extension and a simple paid upgrade flow. The experience for the user would be a lot better even if it makes it a little more complicated to develop. You can use
https://extensionpay.com for a simple way to take payments in your extension either way.