Personalization for Joe Public

"This points to the other reason CMS vendors are moving away from personalization: it is hard and expensive. Personalization is expensive at design-time (to account for permutations); at author-time (adding scads of metadata, just right -- errors here can lead to embarrassing results); at release-time (testing all those permutations); and at run-time (you may need several multiples of server power for the degree of dynamism you're seeking). So make sure you are really adding value for your customers, and calculate your ROI very carefully..."