Well, your credit score doesn't increase merely by applying for more cards. If anything, applying for credit cards will push your score down for a while. Depending on how negatively the new card affects your Average Age of Accounts, your utilization (both total utilization, and individual card utilization), plus the ding for recent credit inquiry, ding for recent new credit line, etc, etc. Well, its complicated...
Basically, if you want to see your credit score increase, you need to make no mistakes (ie, always pay in full and on time, etc) and stop applying for new lines of credit. That will let the inquiries age, will get rid of the ding for recent credit, and will increase your Average Age of Accounts.
By the way, exactly what cards do you have, what are each of their limits and how much are each being utilized? And when did you obtain each one?
