DotNetNuke has had a reputation for a while now that it is not a good platform to work in if you need to have an aggressive search engine strategy. The main reason for this being that out of the box, DNN has terrible issues with duplicate content. Other factors are the less than optimal url structure and the often noted “code bloat”.
The duplicate content issue and url structure problems can both be fixed very easily with the same module. “Code bloat” is a non-issue… or I should say that DNN code bloat is nowhere near severe enough to be an issue. Website code is fairly heavy these days. With increased functionality, responsive design, css based layouts, etc, websites are just code heavy. The search engines are smart enough to decipher content from code.