Online shopping and improved logistics have changed the game. All sectors of the economy have been effected.
If you are selling a product that can be bought cheaper from an online source, that stream of revenue will eventually dry up. Also, if you are not taking advantage of outsourcing opportunities to be able to bring a product to your customer at a more competitive price, you will lose business to your competitor that does.
The sign business has an advantage over many other businesses in that, in most cases, somebody has to install the sign. Usually it takes a contractor's license, specialized training, and equipment. So if somebody buys a sign online, they will likely need an installer. Many forward thinking businesses are gearing up to accept that role, making the process painless, easy and competitively priced. I encourage my clients to look online to try to find the best deal. I'll even send them links to the websites. If I can't furnish the product for them at a competitive price, I really don't want to do it. But I let them know that I appreciate having an opportunity to do the installation.