I have a range of data that I know about people who are our customers (eg. age, gender, region, interests in specific topics, company size, job level) I also know the transactions for these people (how much they paid for different products the company offers and what they bought).

I was thinking about doing a factor analysis in SPSS (principal component analysis with varimax rotation) and set the number of factors to the number of variables I use in the analysis (I don't want to create groups just to see contribution of each). I want to run this analysis on people who were customers of the product. As I deal with a large number of nominal variables I would set these to dummy variables (0/1). I would also standardize all variables (even the dummies). How can I tell which variable contribute to the decision making? Would the Total variance explained table, % of variance tell me the figure I'm after? Is this the right method to approach the issue? I'm open to any suggestions if I started with the wrong methodology.

Many thanks!