Hi SEO 4 Attorneys, it could be any thing is this for your site for a clients site.It could be an attempt at negative SEO from a competitor? The thing is people may try to push 100's of spammy links to a site in hopes to knock it down. In the end of the day my best advice is to monitor your link profile on a weekly basis. Try to remove negative links where possible if you cant remove them then opt for the disavow tool as a last resort. 

Search engines (especially Google) are unpredictable. No matter how adept you are at using the AdWords keyword planner or how targeted your SEO strategy is, you can never be completely sure which of your blog posts or even your landing pages will perform the best — and which keywords they’ll rank for when they do. You’ve got to hit publish, then wait to see how the results shake out over time (and it can take months for a post to gain, or not gain, the traction you’re looking for).

I don't generally think of my own list as a traffic source, because those are people that subscribed and keep coming back, mostly because of good content. This is more tutorial about where to get fresh traffic from in case a person is not using some of these sources already. Where have you guest posted, I haven't seen any, would like to read some of those :)

Guest blogging purely for inbound links is a flawed strategy because the value of those links are going down. However, guest blogging for traffic is still an incredibly viable strategy. While that inbound link you get at the end of a guest post doesn’t have as much SEO value as it used to, it still has the value of exposing your content to a new audience.

Absolutely nothing (other than the scale of the challenge). Google doesn’t care whether you’re a startup, a major financial institution or the smallest online retailer – all it cares about is connecting people with the most relevant content for each search query. The SEO requirements for a startup are exactly the same as the world’s biggest brands and search engines want to see the same things from you as any other kind of business.

It increases relevancy: Siloing ensures all topically related content is connected, and this in turn drives up relevancy. For example, linking to each of the individual yoga class pages (e.g. Pilates, Yoga RX, etc) from the “Yoga classes” page helps confirm—to both visitors and Google—these pages are in fact different types of yoga classes. Google can then feel more confident ranking these pages for related terms, as it is clearer the pages are relevant to the search query.
Mobile traffic: In the Groupon experiment mentioned above, Groupon found that both browser and device matter in web analytics’ ability to track organic traffic. Although desktops using common browsers saw a smaller impact from the test (10-20 percent), mobile devices saw a 50 percent drop in direct traffic when the site was de-indexed. In short, as mobile users grow, we are likely to see direct traffic rise even more from organic search traffic.