Go to your Website->Mailpoet->Settings->Forms and create a new html formular shortcode which looks like this;
[wysija_form id="1"]
Copy the example html code below into mashshare->settings->visual->subscribe content
.
<div class="email-subscription"><strong class="title">Sign up today and be notified about discounts and new Mashshare add-ons</strong>[wysija_form id="1"]<span class="note" style="font-size: 12px;">We promise not to spam you and not to give away your mail address. Read our <a href="/privacy">privacy policy</a>.</span></div>
<div>
<div style="float: left; padding-right: 10px; margin-top: 4px;"><strong class="title">Don't forget to like Mashshare: </strong></div>
<div style="margin-top: 10px;"><iframe width="300" height="150" style="border: none; overflow: hidden; width: 90px; height: 21px;" src="//www.facebook.com/plugins/like.php?href=https%3A%2F%2F.facebook.com%2Fmashshare.net&width=90&layout=button_count&action=like&show_faces=true&share=false&height=21&appId=317697668417910" frameborder="0" scrolling="no"></iframe>
<iframe width="300" height="150" style="width: 200px; height: 21px;" src="//platform.twitter.com/widgets/follow_button.html?screen_name=mashshare&lang=en&show_count=true" frameborder="0" scrolling="no"></iframe></div>
</div>