Unless you are a heavy hitter yourself, you cannot compete with the heavy hitters of e-commerce. The best thing you can do to become relevant is to fill a niche market. Think about what you have to offer that is unique from other companies. Why should people choose you instead of the heavy hitters?
Once you have the answers to those questions, you can market yourself by promoting yourself as unique. Once you develop a solid market, you can continue to grow and maybe eventually become a heavy hitter and compete with those who right now are out of your league.