I measure my credit using credit Karma (free) and I have yet to see a significant (any) drop due to credit applications - I have about 5 in the past 4 months. Where I did take a hit is with the AA cards, which do not report the credit line and thus show high credit utilization as you are doing your required spend, luckily the SP Amex does report the credit line so things are looking better. I'm also getting hit as my average age of open lines decreases.