why do I have to type in the number that appears 8-9 times when contacting a seller

[fitzless]

Twice today I have attempted to ask sellers a question about their item and it asks me to type in a 6-7 digit scrambled number...over and over again...an average of 8-9 times because it tells me the number I typed in  is incorrect...but it clearly is not...is this Ebays way of frustrating buyers and discouraging them from buying???

[reallynicestamps]

That's a captcha and it is a security measure.

You can also have it 'speak' the code to you, which is sometimes easier.