Does this mean we can limit ourselves to Email marketing?

No. Along with so many advantages there are a few potential short comings of Email marketing. Some of them are:

i. Design Problem: Your email should be mobile friendly and also look same in other email clients like Outlook and Gmail etc. So, there’s always a problem to choose between a better design and functionality. Some designs look good on mobile phone screens but not on outlook page.

ii. Time and skills: Sending personalized mails is a little more time consuming and also you will need a skilled person to create a right copy and design as per the mailing list.

iii. Size issues: If the email is a bit longer and suppose it has images it will take long to download and the audience may lose interest and will not wait and skip the email.

iv. Undelivered emails: Emails with poor design or use of certain spam keywords remain undelivered. Keep a check on your mailing list. Wrong email address will also not reach the right person you are trying to send your e-mail to.

v. Spam email: If your email is not targeted to the relevant audience the person receiving it might treat it as a spam and opt out.

So, what we actually need is a good mix of all these mediums of marketing.