Yes a pain in the backside - mainly because there is no checking whatsoever or a way to even do a check to see if a) the user even has a android phone or b) they already have AMS installed on their android phone.
Whilst as RejZoR said the my.avast.com account essentially has that information - but should the information contained there be used to target ads. Many will say no as that is essentially a breach of privacy or trust or at worst adware if the information contained there were to be used in this way.
Not only is it pointless and annoying as mentioned - the frequency is unbelievable, I didn't keep specific count, but I guess it got very boring after having seen it more than five times (when does it bl00dy stop). Add to that it happens on both my systems so double hassle.
I guess it is time to delve into the avast5.ini file to see if a tweak will kill it.