Yeah both are good way to increase business.
Bathrooms, Bathroom Suites
I think it depends on the product, but before I decided on any the first thing I would do is A/B testing and make sure the website is optimized for the highest conversion rate so when people are finally coming to the website It's not just a waste.
Email marketing is really only effective if you are sending to customers who opted in for mailing updates. And even then you'll find people who don't really appreciate receiving some of the things you send. Just as anything else, though, the success of this venture depends on how well you implement the strategy.
There are many blogsite that has great information regarding affiliate marketing and email marketing. Both are beneficial who has online business but don't just depend on both you need to do SEO so that customer could see your site.