I fail to see why this is such a problem? I like the fact you have the signature. Not only does it explain why your post might be brief, it also explains why their maybe punctuation or spelling errors. I had a PM from a moderator on one of the forums I visit today asking me to turn it off. I gracefully declined and asked for the reason. I've had no reply yet.
I think this should be seriously be reconsider, maybe have the option to set their own signature in the setting.
because people already have forum sigs so in effect they end up with two sigs, one of which looks like part of their post.
My opinion is if you paid for this all then you need to have the abilty to remove the advertising from your signature or disable it period. What would be nice is if this app would just enharent the members signature that is already set I'm the members cp and allow the admin a choice to use images or not in the signature line.