I got an email recently asking me to code a website from scratch (waaaayyyy beyond my capabilities) and also asking about three things on websites that "people find annoying".
The sender had asked people she knew about slideshows, sign-up advertisements and smart comments when choosing to opt out, because she'd heard these three things are annoying.
She asked how I'd improve them and I thought I'd share what I had to say. I hope it helps.
1) Having to scroll through slideshows
People are attracted to articles and blog posts like "10 ways to save money" but they don't like manually scrolling through each screen. This seems especially true on mobile devices where there isn't a simple way to get back to what you were reading before.
You can make it much better by adding a "view all" option or simply list the lot in the first place.
2) "Sign-up" pop-up advertisements
These didn't annoy everybody, but what did annoy everybody was them popping up immediately. Don't expect anybody to give you their email address before they've had a chance to look at what you have to say.
You could set it to pop up after they've finished an article or two and have an optional sign-up form prominently placed in the sidebar or at the bottom of each article.
3) 'Smart' opt-out comments on pop-ups
Connected with number 2, many people find some of the comments where you click to not sign up on the sign-up ads annoying and condescending. Things like "No, thanks. I'm happy being broke" or "No, thanks. I like being fat and unhealthy" can turn people off what you do even if they liked it before.
A simple "No, thanks" is fine and polite.