Hulu, the site where you can watch the latest episodes of many popular TV shows, announced a number of site improvements on its blog today. From a business perspective, the most relevant is probably the Ad Tailor, which helps Hulu deliver more personalized ads to viewers.

The site had already taken a step in this direction by giving viewers the ability to give an ad a thumbs up or a thumbs down. However, it will be switching the question to a new format, asking, “Is this ad relevant to you?” and offering “yes” and “no” as possible answers.

Sound arbitrary? Eugene Wei, the vice president of product who wrote the blog post, says it’s not:

The new wording is deliberate since the thumbs up and down iconology might suggest that we were interested primarily in your subjective opinion of the ad creative when what’s more critical for us is understanding whether the product or service being shown is relevant to you. We can’t alter our advertisers’ creative, but we can control which ads we show you. We’ll use your feedback to adjust which ads we show you in the future.

Wei says Hulu will also start asking users to occasionally fill out short surveys. If you fill out the survey, you don’t have to watch an ad. Together, these show a refinement of Hulu’s advertising model. If the site (a joint venture between News Corp., NBC Universal and Disney) can show advertisers that their ads are reaching the right viewers, it should be able to charge more for each eyeball.

Hulu may be trying to make money beyond advertising — it’s reportedly developing a subscription “Hulu Plus,” service too. Peter Yared, founder and chief of social app development company Transpond, wrote a column for us arguing that Hulu’s business model isn’t paying off as promised, which will lead television networks to experiment with their own online services.

The other features revealed today include the ability to adjust video quality depending on your connection speed, a heat map that shows which segments attract the most viewers, and a bigger video player. Wei also touches on the ongoing debate about whether web publishers should be switching from Adobe’s Flash technology to HTML5, the latest version of the basic format of the web. He argues that HTML5 isn’t ready for Hulu’s needs:

Our player doesn’t just simply stream video, it must also secure the content, handle reporting for our advertisers, render the video using a high performance codec to ensure premium visual quality, communicate back with the server to determine how long to buffer and what bitrate to stream, and dozens of other things that aren’t necessarily visible to the end user. Not all video sites have these needs, but for our business these are all important and often contractual requirements.

That’s not to say these features won’t be added to HTML5 in the future (or be easier to implement). Technology is a fast-moving space and we’re constantly evaluating which tools will best allow us to fulfill our mission for as many of our customers as possible.