How to earn money using Twitter?

I have started a website which needs signups of my visitors through emails. Should I use a CPC network or a CPA network to promote it? CPC networks are good but they need much more money and I don't know the ROI will be how good??

SEO Tools are more important for website analysis. SEO tools help to gain traffic and appearance in organic listing based on relevant user queries or keywords in foremost significant Search Engines like Google, Bing, and MSN. I share SEO Tools for Website Analysis in 2015

Most important uses of Google Webmaster tools:
1. Register for email notifications
2. Set preferred domain
3. Crawler and access errors
4. Fetch as Google
5. Search queries, links to your site and Internal links

I want to avoid link penalty from penguin updates. Tel me your suggestion.

How content is playing role in seo and how helping in improving ranking

I am seeing a lot of change in the Local SERP's. Is anyone noticing the same??

I had came across this wordpress theme site they sake themes and plugins. All of there themes has a fixed prices of $19. It seems a bit fishy all other premium wordpress theme site charge much more than this. Is this site reliable? If anyone will share any experiences with them then it will be much helpful.

I have seen many landing pages who makes false promises to get more and more signups. Isn't this thing hurting the entire conversion process I mean they may get signups now but it will not last long, right?

How to use effectively hashtags in social media networks such as Facebook and twitter to get maximum output from every posts??