If I were going to start a web-based business today, this is what that business would be.
WordPress Startup Theme (& Community)
There is plenty of money to be made in WordPress themes. Don't just take me at my word... here are some data points to consider:
WooThemes was worth reportedly $2,000,000+ as far back as 2010, and in February of 2013 the WooThemes owner tweeted they had surpassing 400,000 customers. This is an estimated revenue in the $40,000,000 range for their lifetime.
Theme marketplaces like ThemeForest have (at the time of writing) about 14,000 WordPress themes offered for download. To my knowledge, all of the themes on themeforest are created by individuals who collect a percentage of the revenue that Themeforest generates on their theme. The highest theme in sales was by theme creator Themefusion and has 56,000 sales of just one theme (Avada). At $55 a pop, Avada has generated $3,080,000 in revenue for Themeforest and Themefusion.
If you think that Themefusion's Avada theme is a freak occurrence, you would be partially right. Most themes do not sell 56,000 copies. But you have to go 215 pages deep into Themeforest's theme listings (when ranked by number of sales) to find themes that have sold less than 100 copies. This means Themeforest has about 6450 themes that have sold one hundred or more copies.
That's a lot of WordPress themes.
But we know the presence of a market doesn't necessarily mean there is a business opportunity. The next question is what, if anything, could a new theme company do to disrupt the market and take on the incumbents?
Sophisticated business owners primarily want their wordpress theme to push their business' KPIs (time on site, conversion rate, etc.) and very few themes target this customer need. A theme that was built on sound Usability, SEO, and Conversion Rate Optimization principles would be able to segment the existing market into two markets: aesthetic-focused (almost all current themes are based on this) and KPI-focused (the new market).
How to Monetize:
I would personally release the theme for free initially in order to get traction and then eventually ratchet up the theme's cost as you get a feel for the market and you move past early adopters and into the larger market.
The real streams of income would come from the following:
Custom Development: Within the theme's files would be modifications to the dashboard of the user's WordPress theme that allowed the user to make custom development requests for their theme. A group of developers who know this particular theme inside and out would bid on the jobs. The bids would be more accurate due to the developer's familiarity with the theme, and the jobs would likely be much faster for the same reason.
Support: No surprises here, but support tickets could generate recurring revenue for the firm and alleviate the customer's pain in finding freelance developers.
Hosting, Backups, Etc: Productize common requests from customers and do so in a way that creates revenue for the theme company but also works for the customer.
In summary, I think the tack this theme company would take is to solve the theme purchasers ultimate pain point- sales for their company- rather than trying to sell a theme on only appearance or features. The customers this company would acquire would be an excellent demographic to work with for many years and would generally be agreeable to theme enhancements that drove the needle in their business.