Is there an SEO disadvantage to using responsive design instead of separate mobile URLs?

Does a site leveraging responsive design “lose” any SEO benefit compared to a more traditional m. site?
John E, New York

Should I add schema.org markup on my videos even if they’re on YouTube?

Rich snippets are automatically added to SERPs for video results from YouTube. Is it recommended to add schema video markup onsite in order to get your page w/embedded video to rank in SERPs in addition to the YouTube result, or is this redundant?
cliquekaila, Phoenix

Can nofollow links hurt my site’s ranking?

I’m building links, not for SEO but to try and generate direct traffic, if these links are no-follow am I safe from getting any Google penalties? Asked another way, can no-follow links hurt my site?
Tubby Timmy, UK

Learn about rel=”nofollow”: https://support.google.com/webmasters…

How does Google treat hidden content which becomes visible when clicking a button?

How does Google treat hidden content which becomes visible when clicking a button? Does it look spammy if most of the text is in such a section? (e.g. simple page to buy something and “show details” button which reveals a lot of information about it.)
Thomas Greiner, Cologne

SEO Marketing Emails

We all get a constant flow of emails from SEO companies across the globe. We even get them ourselves but reading Matt Cutts blog even Google get them.

Matts Cutts posted:-

Folks at Google get cold-call emails out of the blue just like everybody else. Here’s an email that a colleague of mine got recently:

I was on your website www.google.com and wanted to shoot you a quick note. I think I can make a few changes (aesthetically and/or SEO – wise) to make your site convert more visitors into leads and to get it placed higher in the organic search results, for a few of the select terms.

This is NOT like one of those foreign emails you probably get in your inbox every day. Just to be upfront I have 3 agents that work with me for development /SEO.

I would just need to know which (if not both) services you’re open to checking out information about, either web design or SEO. Would you be open to seeing more brief info / quote for what I would like to accomplish?

Regards,
XXXXXX XXXXX

So this person is offering help to convert Google visitors into leads. Or, you know, to improve Google’s rankings in organic search results. Sigh.

So this makes us feel much better now knowing that Google are doing this.