FWIW, a long time ago, I started the process of having articles on my website translated into Spanish and French. A lot of people tend to think French is limited to France, but it also covers parts of Canada, Belgium and Switzerland, among others, plus parts of Africa and various locales in the Caribbean. So it is pretty widespread.
That said, I saw more traffic to the Spanish articles than French. But, as a caveat, I never finished having all the articles translated into either language and had more Spanish than French.
If you're going for prestige, I'd choose French next, then Spanish. For money, probably Spanish first, then French.
Also, be mindful that American Spanish (i.e., Spanish as spoken in the Americas) has differences from European (i.e., Spain) Spanish. In my case, I used a translator familiar with American Spanish.