I spent a lot of time over the past 2 years, in Spain and it's relatively easy to start up a business, but being successful is another story.
I met many Brits, a fair mixture of U k nationalities and there were no fantastic stories of success, quite the opposite, the Spanish business and property market is pretty static, with hundreds of businesses of all sorts, for sale or lease transfer.
There are a few people I know, who are happy to be based there and pop over once a month, or so, but they are wealthy people, with substantial businesses over here, which are well managed and they have no money problems.
The young couples who were doing fairly well, had started up, in Spain, the same businesses they knew best and were able to transfer.
These are refrigeration / air con' / general trades / handyman types.