A very similar annoyance is menus that don't wait to be clicked but jump out in your face and obscure the content you wanted to see just because your mouse randomly passed over them.
You click a link to go to an interesting-sounding page. Your mouse is still wherever that link was on the previous page, but now, blammo!, it randomly lands on some menu, which won't wait to find out whether you wanted to see it or not. It just throws up all over the page and leaves you looking for a way to get rid of it.
You scroll the new page a bit, click another link, and blammo, another menu jumps up and covers the new page. You see a link near the top of the page you want to click and as your mouse heads up to it, blammo, you pass over another menu that jumps out and covers what you were trying to click.
Usually, a popup signup ad will stay closed after you close it the first time, but these menus won't EVER stop jumping up in your face. Tooltips or items that highlight themselves in place on hover are no problem, because they don't get in the way, but menus are meant to cover other things. That's why all native OSes have menus wait until users explicitly ask for them.
And touchscreen devices essentially have no hover, so if your menus had to have these obnoxious dynamics for users to discover that they were menus, it would mean that your design was nearly unusable on devices with no mouse. Make your menus obvious to users without a mouse and you no longer have to make them obnoxious to users with a mouse.
Tell your designer friends: when you have caught someone's attention and made them want to see something on your site, don't then suddenly block their view with something they DIDN'T want to see, something they then have to escape from, whether "Sign up now!" or "Click here to tell your friends about us!" or "What do you think of us now?" or "Here's a cascading menu of things you weren't asking for instead of what you wanted!"
You click a link to go to an interesting-sounding page. Your mouse is still wherever that link was on the previous page, but now, blammo!, it randomly lands on some menu, which won't wait to find out whether you wanted to see it or not. It just throws up all over the page and leaves you looking for a way to get rid of it.
You scroll the new page a bit, click another link, and blammo, another menu jumps up and covers the new page. You see a link near the top of the page you want to click and as your mouse heads up to it, blammo, you pass over another menu that jumps out and covers what you were trying to click.
Usually, a popup signup ad will stay closed after you close it the first time, but these menus won't EVER stop jumping up in your face. Tooltips or items that highlight themselves in place on hover are no problem, because they don't get in the way, but menus are meant to cover other things. That's why all native OSes have menus wait until users explicitly ask for them.
And touchscreen devices essentially have no hover, so if your menus had to have these obnoxious dynamics for users to discover that they were menus, it would mean that your design was nearly unusable on devices with no mouse. Make your menus obvious to users without a mouse and you no longer have to make them obnoxious to users with a mouse.
Tell your designer friends: when you have caught someone's attention and made them want to see something on your site, don't then suddenly block their view with something they DIDN'T want to see, something they then have to escape from, whether "Sign up now!" or "Click here to tell your friends about us!" or "What do you think of us now?" or "Here's a cascading menu of things you weren't asking for instead of what you wanted!"