Recently a church communication elder asked me about the effectiveness of electronic church signs. She sent this link in reference to the sign their church was considering: http://curbappealled.com/. She added that a church member had donated the money for it and asked for my comments on it. I'm always happy to respond to requests from church communicators and though I can't guarantee how quickly I will respond, please send questions or suggestions for content on this site to: firstname.lastname@example.org.
First, I'd like to offer some comments on a sign like this and then on signs overall. If you have any more comments on signs, examples of effective signage, or sources for good ones, please add them to the comments below.
As to my answer whether or not to get a professionally designed electronic sign—the answer to this is easy—go for it! Particularly, if the other businesses in your area have similar signs, you want people to be able to clearly find you as a church. Having said that a sign like this can be very good for your church, following are a few other comments that might be helpful.