New Delhi, Sept. 7 -- Getting the right credit card used to mean comparing annual fees, reward rates and perhaps lounge access. For a growing number of cardholders, it now involves something closer to portfolio management.

Which cards should you hold? Which one should pay for groceries, insurance, utilities or a large purchase? Should reward points be converted into airline miles or hotel points, or simply pay the credit card bill? When a card gets devalued, what should replace it? And when it is finally time to travel, which redemption gives the highest value?

A growing number of platforms and independent consultants now provide advice on these questions for a fee. Services vary considerably in scope and price. The Points Code, CardExp...