Word like finance is a high paying word but then it is lot of competition from others and a lot of user searching for that word. A word that dont pay as much often has less competition but less searchers. The get the most out of adsense wich do you go for. If Im not going to work to hard to get inlinks
getting most out of adsense is one thing and getting ranked in search engine that drives traffic is another thing. if you are targeting the keyword finance, thats a broad term. you should actually try to narrow the result to get most targated visitors which will also make iit easier for you to get ranked in SE. for example, "home loan refinancing" or "debt consolidation" or "auto financing" etc